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 Amendment
In view of the amendment, filed on December 23rd, 2025, the following are withdrawn from the previous office action, mailed on August 13th, 2025.
Rejection of claim 22 under 35 U.S.C. 112(a)
Rejections of claims 1, 2, 4-10, 12, 22 and 23 under 35 U.S.C. 112(b)
Response to Arguments
Applicant's arguments in view of the amendments filed June 12th, 2026, have been fully considered but they are not persuasive.
Applicant amends claims 1, 22 and 23 and argues the prior art of record does not teach “the first electrically conductive portion forming the powder particle container comprises a stationary, non-rotating trough”. Examiner respectfully disagrees. The specification fails to provide support for these limitations and as such is rejected under 35 U.S.C. 112(a) in the new grounds of rejection below.
Applicant argues Coward’s “spoke” element 33 does not read on “second electrically conductive portion extending laterally of the first electrically conductive portion and adjacent a surface of the powder particle container”. Examiner respectfully disagrees. In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (“laterally outward”) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See MPEP 2145 (VI). Furthermore, as shown in the annotated Figure 2 of Coward in the prior office action, the “First electrode (second conductive portion)” extends laterally outward and away from “First electrode (first conductive portion)” as required by the claim. The first conductive portion, which functions as a powder container, comprises a surface 16 adjacent the second conductive portion. As such, the structure of Coward reads on the recited limitations of the claim.
Applicant argues Kelkar’s distribution member 432 is not involved in electric field generation. Examiner respectfully disagrees. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See MPEP 2145 (IV). The rejections of the claims are based on a combination of Coward and Kelkar, wherein Coward teaches a first electrode (Fig. 2, portions 28 and 33; see annotated figure 2 below) including a first electrically conductive portion (Fig. 2, 28; see annotated figure 2 below; [0033] the entire structure 14 including 28 is electrically conductive) forming a powder particle container for containing a quantity of the powder particles therein ([0030], powder particles 13 on powder landing surface 18 of a circular trough; see annotated figure 2 below) and a second electrically conductive portion (Fig. 2, 33; see annotated figure 2 below; [0033] the entire structure 14 including 33 is electrically conductive) extending laterally of the first electrically conductive portion and adjacent a surface of the powder particle container (portion 33 is extending laterally of the portion 18 and adjacent a surface 16 of the powder particle container 15). Coward teaches the structure 33 has openings for the powder to be removed from groove 17 and fall through (Fig. 3, see spaces between the three bars). Coward does not teach the structure of the second electrically conductive portion of the first electrode is a planar mesh structure having openings sufficient in dimension to enable the powder particles to pass through. However, in the analogous art Kelkar teaches a device for supplying powder to a powder bed during an additive manufacturing process (Abstract), comprising a planar mesh structure having openings sufficient in dimension to enable the powder particles to pass through ([0050], the distribution member 432 having a series of openings along the bottom surface for allowing powder to fall through). Coward and Kelkar are both considered to be analogous to the claimed method because they are in the same field of additive manufacturing. Therefore, it would be obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the electrically conductive structure in Coward to incorporate a mesh as taught by Kelkar as described above, in order to selectively allow powder particles to fall through by controlling the size of the openings since it’s important to keep size consistency in the powder distribution device (Kelkar, [0009]). As such, the combination of Coward and Kelkar teaches a first electrode with a planar mesh portion as required.
Applicant’s amendments to the claims necessitate a new grounds of rejection provided below.
New Grounds of Rejection
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1, 2, 4-7, 9, 10, 12, 22 and 23 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 recites the limitation “the planar mesh structure is electrically isolated from the powder particle container and is maintained at a fixed potential independent of the powder particle container” in lines 9-11. The specification fails to provide support for this limitation. "While there is no in haec verba requirement, newly added claims or claim limitations must be supported in the specification through express, implicit, or inherent disclosure." See MPEP 2163 (1B). While applicant points to Figure 1 and [0026] as support, there is nothing in these recited sections of the specification to support the recited limitation.
Claim 1 recites the limitation “the first electrically conductive portion forming the powder particle container comprises a stationary, non-rotating trough” in lines 25-26. The specification fails to provide support for this limitation. "While there is no in haec verba requirement, newly added claims or claim limitations must be supported in the specification through express, implicit, or inherent disclosure." See MPEP 2163 (1B). Furthermore, negative limitations in the claims must have support in the specification to satisfy the description requirement of 35 U.S.C. 112. See MPEP 2173.05 (i). Note that the mere absence of a positive recitation is not basis for an exclusion. While applicant points to Figure 1 and [0026] as support, there is nothing in these recited sections of the specification to support a stationary, non-rotating trough.
Claim 22 recites the limitation “the first electrically conductive portion is a stationary, non-rotating structure” in lines 10-11. The specification fails to provide support for this limitation. "While there is no in haec verba requirement, newly added claims or claim limitations must be supported in the specification through express, implicit, or inherent disclosure." See MPEP 2163 (1B). Furthermore, negative limitations in the claims must have support in the specification to satisfy the description requirement of 35 U.S.C. 112. See MPEP 2173.05 (i). Note that the mere absence of a positive recitation is not basis for an exclusion. While applicant points to Figure 1 and [0026] as support, there is nothing in these recited sections of the specification to support a stationary, non-rotating trough.
Claim 23 recites the limitation “the first electrically conductive portion forming the powder particle container comprises a stationary, non-rotating trough” in lines 9-10. The specification fails to provide support for this limitation. "While there is no in haec verba requirement, newly added claims or claim limitations must be supported in the specification through express, implicit, or inherent disclosure." See MPEP 2163 (1B). Furthermore, negative limitations in the claims must have support in the specification to satisfy the description requirement of 35 U.S.C. 112. See MPEP 2173.05 (i). Note that the mere absence of a positive recitation is not basis for an exclusion. While applicant points to Figure 1 and [0026] as support, there is nothing in these recited sections of the specification to support a stationary, non-rotating trough.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are:
Claims 1, 22, and 23 recite “a signal source for applying an electrical signal across the first and second electrodes to create an electric field between the first and second electrodes” which is interpreted under requirements of 35 U.S.C. 112(f). The above limitation includes the structural generic placeholder of “a signal source” followed by functional limitation of “for applying an electrical signal across the first and second electrodes…”. The specification defines “DC power source (12)” and “AC signal source (12’)” as corresponding structure for the structural generic placeholder of “a signal source”. Claims 6-7 are not interpreted under 112(f) as having pertinent structure “the second electrode” and “the signal source”.
Claims 2 and 10 recite “a movement mechanism for moving the first electrode and the second electrode over the powder bed” which is interpreted under requirements of 35 U.S.C. 112(f). Specification defines “stepper motor operably associated with structure supporting the counter electrode 16” as corresponding structure for the claimed structural generic place holder of “movement mechanism”.
Claim 22 recites “a movement subsystem configured to create relative movement of the first and second electrodes relative to the powder bed” which is interpreted under requirements of 35 U.S.C. 112(f). Specification defines “counter electrode subsystem 216” as corresponding structure for the claimed structural generic place holder of “movement subsystem”.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
Claim 6 recites “the powder particles comprise non-conductive powder particles” which is interpreted as the intended use of a claimed apparatus. It’s noted that the intended use of a claimed apparatus is not germane to the issue of the patentability of the claimed structure. If the prior art structure is capable of performing the claimed use then it meets the claim. See MPEP 2115.
Please note that in the absence of support for the limitations outlined in the 35 U.S.C. 112(a) rejections above, the claims are being interpretated with only the language having support in the specification.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 2, 4, 10, 12, and 22-23 are rejected under 35 U.S.C. 103 as being unpatentable over Coward (US 20190283982 A1), in view of Kelkar et al. (US 20190060998 A1; hereafter Kelkar).
Regarding claim 1, Coward discloses a powder particle deposition system (Abstract, A powder feeder) for use with an additive manufacturing system, for moving powder particles without physical contact to recreate a powder bed, the powder particle deposition system comprising:
a first electrode (Fig. 2, portions 28 and 33; see annotated figure 2 below) including a first electrically conductive portion (Fig. 2, 28; see annotated figure 2 below; [0033] the entire structure 14 including 28 is electrically conductive) forming a powder particle container for containing a quantity of the powder particles therein ([0030], powder particles 13 on powder landing surface 18 of a circular trough; see annotated figure 2 below) and a second electrically conductive portion (Fig. 2, 33; see annotated figure 2 below; [0033] the entire structure 14 including 33 is electrically conductive) extending laterally of the first electrically conductive portion and adjacent a surface of the powder particle container (portion 33 is extending laterally of the portion 18 and adjacent a surface 16 of the powder particle container 15);
a second electrode (electrode 21) disposed over an upper surface of the powder particle container and over the second electrically conductive portion, and arranged non-parallel to the powder particle container and non-parallel to the second conductive portion, and extending laterally of the powder particle container (Fig. 8, electrode 21 is disposed over the powder particle container under 23 and over the second conductive portion 33, and is non-parallel to the powder particle container, extending laterally of the powder particle container 15; see annotated figure 2 below);
and a signal source for applying an electrical signal across the first and second electrodes ([0029], voltage supply 20 is an electrical signal applied between first electrode 21 and second electrode wheel 14) to create an electric field between the first and second electrodes ([0030], electric field created within space 22 between powder landing surface 18 and revolving under electrode 21), the electric field varying in strength over a length of the powder particle (Fig. 7-8, the electrode 21 is tilted and therefore the electric field varies in strength in the horizontal direction in the space between the electrode 21 and the powder particle container), the varying strength electric field causing the powder particles to move upwardly and laterally out from the powder particle container toward the second electrode, and then to be repelled from the second electrode and to fall through the second electrically conductive portion onto the powder bed (Fig. 8, [0041], The electrode geometries of FIGS. 7 and 8 impart horizontal motion to oscillating particles 13. As powder particles 13 collide with the angled lower surface of insulator 23, they are reflected outward and over edges 16, 17 of rim 15).
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Coward teaches the second electrode maybe disposed at an angle of between 1 degree to 90 degrees relative to the powder particle container and the second conductive portion of the first electrode (Fig. 8; [0041]), but does not explicitly teach an angle of between 5 degrees to 70 degrees. However, it would have been obvious to one having ordinary skill in the art at the time of the invention was made to optimize the range of the angle between the second electrode and the powder particle container to between 5 and 70 degrees, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. As powder particles collide with the angled lowered surface of the second electrode, they acquire horizontal movement that accelerates their movement out of the powder particle container ([0041]). In order to ensure faster groove clearing, it would be obvious to one of ordinary skill in the art to vary the angle between the second electrode and the powder particle container. One would have been motivated to make this optimization for the purpose of accelerating powder movement out of the powder particle container ([0041]). Furthermore, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05.
Coward further teaches the first electrode is formed by the powder particle container ([0030], “The electric field created within space 22 created by powder landing surface 18 and electrode 21 to develop an electrical surface charge) and a structure (Fig. 2, 33) supported above the powder bed and laterally of the powder particle container (See annotated Fig. 2, above), the structure helping to form a portion of the electric field that extends laterally beyond the powder particle container (See annotated Fig. 2, above, 33 is under a portion of the second electrode 21, extends laterally beyond the container 15, and helps to form a portion of the electric field). Coward teaches the structure 33 has openings for the powder to be removed from groove 17 and fall through (Fig. 3, see spaces between the three bars). Coward teaches the second electrode comprises a stationary, planar electrode disposed at said angle over both the powder particle container and the planar mesh structure simultaneously (Fig. 8; [0041]).
Coward does not teach the structure of the second electrically conductive portion of the first electrode is a planar mesh structure having openings sufficient in dimension to enable the powder particles to pass through, and the planar mesh structure is non-parallel.
However, Kelkar teaches methods for supplying powder to a powder bed during an additive manufacturing process (Abstract), comprising a planar mesh structure having openings sufficient in dimension to enable the powder particles to pass through ([0050], the distribution member 432 having a series of openings along the bottom surface for allowing powder to fall through), and the planar mesh structure is non-parallel (Fig. 4A, structure 432 is non-parallel to the structures above it).
Coward and Kelkar are both considered to be analogous to the claimed method because they are in the same field of additive manufacturing. Therefore, it would be obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the electrically conductive structure in Coward to incorporate a mesh as taught by Kelkar as described above, in order to selectively allow powder particles to fall through by controlling the size of the openings since it’s important to keep size consistency in the powder distribution device (Kelkar, [0009]).
Examiner notes that the combined structure of modified Coward still allows for the function of powder deposition when the trough and second electrode are stationary as evidenced by specification paragraph [0043] of Coward, “Using electrode 21 alone to evacuate groove 26 results in excellent low and mid-range flow rates, but a lower maximum powder flow rate.” It has been held that disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. See MPEP 2123 (II).
Regarding claim 2, Coward further teaches a movement mechanism ([0029] rim 15) for moving the counter second electrode relative to the powder particle container ([0029], rim 15 rotates (revolves) under hopper 12; [0032], wheel 14 rotates groove 26 beneath electrode 21).
Modified Coward does not teach a movement mechanism for moving the first electrode and the second electrode over the powder bed.
However, Kelkar further teaches a movement mechanism for moving the powder particle container and the second electrode over a powder bed ([0031], the movement of the recoater apparatus 300 can be controlled; and since the powder feeder in Coward comprises of the powder particle container and the second electrode, Kelkar teaches moving the entire powder recoater assembly over a powder bed which includes moving all components within the powder recoater over the powder bed).
Coward and Kelkar are both considered to be analogous to the claimed method because they are in the same field of additive manufacturing. Therefore, it would be obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have incorporated a movement mechanism in Coward to incorporate moving both the second electrode and the powder particle container relative to a powder bed as taught by Kelkar in order to precisely supplying the powder particles to the powder bed (Kelkar, [0042]).
Regarding claim 4, Coward further teaches the second electrode comprises a counter electrode (Fig. 1, electrode 21 is a counter electrode); and the powder particles comprise electrically conductive powder particles ([0004], “metallic or conductive powders”).
Regarding claim 10, Coward further teaches a movement mechanism ([0029] rim 15) for moving the counter second electrode relative to the powder particle container ([0029], rim 15 rotates (revolves) under hopper 12; [0032], wheel 14 rotates groove 26 beneath electrode 21).
Regarding claim 12, Coward further teaches the second electrode comprises a plurality of independent electrode elements that are controlled independently of one another ([0041]- [0042], multiple electrodes’ voltage, electrode stand-off distance, size, etc. can be adjusted to be different for each electrode).
Regarding claim 22, Coward teaches a powder particle deposition system (Abstract, “A powder feeder”) for use with an additive manufacturing system ([0004]), for moving powder particles without physical contact to recreate a powder bed ([0012] the present invention involves powder feeder with electrostatic forces that cause the movement of the particles, thus free of physical contact to the powder bed), the powder particle deposition system comprising:
a first electrode (Fig. 2, portions 28 and 33; see annotated figure 2 below) including a first electrically conductive portion (Fig. 2, 28; see annotated figure 2 below; [0033] the entire structure 14 including 28 is electrically conductive) forming a powder particle container for containing a quantity of the powder particles therein ([0030], powder particles 13 on powder landing surface 18 of a circular trough; see annotated figure 2 below) and a second electrically conductive portion (Fig. 2, 33; see annotated figure 2 below; [0033] the entire structure 14 including 33 is electrically conductive) extending laterally of the first electrically conductive portion and parallel a surface of the powder particle container (portion 33 is extending laterally of the portion 18 and parallel a surface 16 of the powder particle container 15);
a second electrode (electrode 21) disposed over an upper surface of the powder particle container and over the second electrically conductive portion, and arranged non-parallel and at an angle to the powder particle container and non-parallel to the second conductive portion, and extending laterally of the powder particle container (Fig. 8, electrode 21 is disposed over the powder particle container under 23 and over the second conductive portion 33, and is non-parallel to the powder particle container, extending laterally of the powder particle container 15; since the second electrode is non-parallel to the first electrode, it’s necessary to form a common angel; see annotated figure 2 below);
and a signal source for applying an electrical signal across the first and second electrodes ([0029], “voltage supply 20 in electrical communication with electrode 21 and wheel 14”) to create an electric field between the first and second electrodes ([0030], electric field created within space 22 between powder landing surface 18 and revolving under electrode 21), the electric field varying in strength over a length of the powder particle (Fig. 7-8, the electrode 21 is tilted and therefore the electric field varies in strength in the horizontal direction in the space between the electrode 21 and the powder particle container), the electric field causing the powder particles to move upwardly and laterally out from the powder particle container toward the second electrode, and then to be repelled from the second electrode and to fall through the second electrically conductive portion onto the powder bed (Fig. 8, [0041], The electrode geometries of FIGS. 7 and 8 impart horizontal motion to oscillating particles 13. As powder particles 13 collide with the angled lower surface of insulator 23, they are reflected outward and over edges 16, 17 of rim 15).
Coward teaches the second electrode is disposed at an angle of between 1 degree to 90 degrees relative to the powder particle container and the second conductive portion of the first electrode (Fig. 8; [0041]), but does not explicitly teach an angle of between 5 degrees to 70 degrees. It would have been obvious to one having ordinary skill in the art at the time of the invention was made to optimize the range of the angle between the second electrode and the powder particle container to between 5 and 70 degrees, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. As powder particles collide with the angled lowered surface of the second electrode, they acquire horizontal movement that accelerates their movement out of the powder particle container ([0041]). In order to ensure faster groove clearing, it would be obvious to one of ordinary skill in the art to vary the angle between the second electrode and the powder particle container. One would have been motivated to make this optimization for the purpose of accelerating powder movement out of the powder particle container ([0041]). Furthermore, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05.
Coward teaches the first electrode is formed by the powder particle container ([0030], “The electric field created within space 22 created by powder landing surface 18 and electrode 21 to develop an electrical surface charge) and a structure (Fig. 2, 33) supported above the powder bed and laterally of the powder particle container (See annotated Fig. 2, above), the structure helping to form a portion of the electric field that extends laterally beyond the powder particle container (See annotated Fig. 2, above, 33 is under a portion of the second electrode 21, extends laterally beyond the container 15, and helps to form a portion of the electric field). Coward teaches the structure 33 has openings for the powder to be removed from groove 17 and fall through (Fig. 3, see spaces between the three bars). Coward does not teach the structure of the second electrically conductive portion of the first electrode is a planar mesh structure having openings sufficient in dimension to enable the powder particles to pass through, and the planar mesh structure is non-parallel. Additionally, Coward does not teach a movement mechanism for moving the first electrode and the second electrode over the powder bed.
However, Kelkar teaches methods for supplying powder to a powder bed during an additive manufacturing process (Abstract), comprising a planar mesh structure having openings sufficient in dimension to enable the powder particles to pass through ([0050], the distribution member 432 having a series of openings along the bottom surface for allowing powder to fall through), and the planar mesh structure is non-parallel (Fig. 4A, structure 432 is non-parallel to the structures above it), and a movement mechanism to create relative movement of the first and second electrodes relative to the powder bed, such that the relative movement occurs along a common longitudinal path, while maintaining an angular orientation of the second electrode constant relative to an axis extending normal to the common longitudinal path, to deposit the powder particles onto the powder bed ([0031], The recoater apparatus mounted to a track system, such that the movement of the recoater apparatus 300 can be controlled along the x-axis, y-axis, and/or the z-axis; since the powder feeder in Coward comprises of the powder particle container and the second electrode, Kelkar teaches moving the entire powder recoater assembly over a powder bed which includes moving all components within the powder recoater over the powder bed, while maintaining a constant angular orientation of each component within the powder recoater).
Coward and Kelkar are both considered to be analogous to the claimed method because they are in the same field of additive manufacturing. Therefore, it would be obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the electrically conductive structure in Coward to incorporate a mesh as taught by Kelkar as described above, in order to selectively allow powder particles to fall through by controlling the size of the openings since it’s important to keep size consistency in the powder distribution device (Kelkar, [0009]) and to have incorporated a movement mechanism in Coward to incorporate moving both the second electrode and the powder particle container relative to a powder bed as taught by Kelkar in order to precisely supplying the powder particles to the powder bed (Kelkar, [0042]).
Examiner notes that the combined structure of modified Coward still allows for the function of powder deposition when the trough and second electrode are stationary as evidenced by specification paragraph [0043] of Coward, “Using electrode 21 alone to evacuate groove 26 results in excellent low and mid-range flow rates, but a lower maximum powder flow rate.” It has been held that disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. See MPEP 2123 (II).
Regarding claim 23, Coward teaches a powder particle deposition system (Abstract, “A powder feeder”) for use with an additive manufacturing system, for moving powder particles without physical contact to recreate a powder bed ([0012] the present invention involves powder feeder with electrostatic forces that cause the movement of the particles, thus free of physical contact to the powder bed), the powder particle deposition system comprising:
a first electrode (Fig. 2, portions 28 and 33; see annotated figure 2 below) including a first electrically conductive portion (Fig. 2, 28; see annotated figure 2 below; [0033] the entire structure 14 including 28 is electrically conductive) forming a powder particle container for containing a quantity of the powder particles therein ([0030], powder particles 13 on powder landing surface 18 of a circular trough; see annotated figure 2 below) and a second electrically conductive portion (Fig. 2, 33; see annotated figure 2 below; [0033] the entire structure 14 including 33 is electrically conductive) extending laterally of the first conductive portion and adjacent a surface of the powder particle container (portion 33 is extending laterally of the portion 18 and adjacent a surface 16 of the powder particle container 15);
a second electrode disposed over an upper surface of the powder particle container and over the second conductive portion, and arranged non-parallel to the powder particle container and non-parallel to the second conductive portion, and extending laterally of the powder particle container (Fig. 8, electrode 21 is disposed over the powder particle container under 23 and over the second conductive portion 33, and is non-parallel to the powder particle container, extending laterally of the powder particle container 15; see annotated figure 2 below);
and a signal source for applying an electrical signal across the first and second electrodes ([0029], “voltage supply 20 in electrical communication with electrode 21 and wheel 14”) to create an electric field between the first and second electrodes ([0030], electric field created within space 22 between powder landing surface 18 and revolving under electrode 21), the electric field varying in strength over a length of the powder particle (Fig. 7-8, the electrode 21 is tilted and therefore the electric field varies in strength in the horizontal direction in the space between the electrode 21 and the powder particle container), the electric field causing the powder particles to move upwardly and laterally out from the powder particle container toward the second electrode, and then to be repelled from the second electrode and to fall through the second electrically conductive portion onto the powder bed (Fig. 8, [0041], The electrode geometries of FIGS. 7 and 8 impart horizontal motion to oscillating particles 13. As powder particles 13 collide with the angled lower surface of insulator 23, they are reflected outward and over edges 16, 17 of rim 15).
Coward also teaches the first and second conductive portions are at a common potential ([0033], “Preferably, wheel 14 and body 11 of powder feeder 10 are both conductive and connected to earth-ground as shown in FIG. 3.” Coward teaches the wheel 14 is composed of container the edges 16, 17, and floor 29, which make up the first portion that holds particles, and the thin spokes 33, which make up the second portion. Since the entire wheel 14 is grounded, both the first and second portions have a common potential of zero.)
Coward teaches the second electrode is disposed at an angle of between 1 degree to 90 degrees relative to the powder particle container and the second conductive portion of the first electrode (Fig. 8; [0041]), but does not explicitly teach an angle of at least 5 degrees. It would have been obvious to one having ordinary skill in the art at the time of the invention was made to optimize the range of the angle between the second electrode and the powder particle container to at least 5 degrees, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. As powder particles collide with the angled lowered surface of the second electrode, they acquire horizontal movement that accelerates their movement out of the powder particle container ([0041]). In order to ensure faster groove clearing, it would be obvious to one of ordinary skill in the art to vary the angle between the second electrode and the powder particle container. One would have been motivated to make this optimization for the purpose of accelerating powder movement out of the powder particle container ([0041]). Furthermore, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05.
Coward teaches the structure 33 has openings for the powder to be removed from groove 17 and fall through (Fig. 3, see spaces between the three bars). Coward does not teach the structure of the second electrically conductive portion of the first electrode is a planar mesh structure.
However, Kelkar teaches methods for supplying powder to a powder bed during an additive manufacturing process (Abstract), comprising a planar mesh structure having openings sufficient in dimension to enable the powder particles to pass through ([0050], the distribution member 432 having a series of openings along the bottom surface for allowing powder to fall through), and the planar mesh structure is non-parallel (Fig. 4A, structure 432 is non-parallel to the structures above it).
Coward and Kelkar are both considered to be analogous to the claimed method because they are in the same field of additive manufacturing. Therefore, it would be obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the electrically conductive structure in Coward to incorporate a mesh as taught by Kelkar as described above, in order to selectively allow powder particles to fall through by controlling the size of the openings since it’s important to keep size consistency in the powder distribution device (Kelkar, [0009]).
Examiner notes that the combined structure of modified Coward still allows for the function of powder deposition when the trough and second electrode are stationary as evidenced by specification paragraph [0043] of Coward, “Using electrode 21 alone to evacuate groove 26 results in excellent low and mid-range flow rates, but a lower maximum powder flow rate.” It has been held that disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. See MPEP 2123 (II).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Coward (US 20190283982 A1), in view of Kelkar et al. (US 20190060998 A1; hereafter Kelkar) as applied in claim 4, and further in view of Larson (WO 2009027078 A1).
Regarding claim 5, modified Coward discloses the system of claim 4.
Modified Coward does not teach a DC signal source.
However, Larson teaches a DC signal source for applying a DC signal to the counter electrode (Page 4, line 15-18, “at least one corona electrode disposed in the powder chamber that is electrically connected, e.g., to a high-voltage direct current circuit and is adapted to charge and/or transfer the masking powder particles”).
Coward and Larson are both considered to be analogous to the claimed method because they are pertinent to the problem of moving powder particles during solid fabrication process. Therefore, it would be obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified a signal source in Coward to incorporate a DC signal applying to the second electrode as taught by Larson in order to create an efficient fluidized powder bed (Larson, Page 10, line 26-29).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Coward (US 20190283982 A1), in view of Kelkar et al. (US 20190060998 A1; hereafter Kelkar) as applied in claim 1, and further in view of Mackie et al. (US 20200368813 A1; hereafter Mackie).
Regarding claim 9, modified Coward discloses the system of claim 1.
Modified Coward does not teach the electrically conductive conducting mesh is held at a ground potential.
However, Mackie teaches the electrically conductive conducting mesh is held at a ground potential ([0058], “In when electron beams are used, the carrier track 16 may be grounded to provide a grounding electrode in electrical communication with the sheet 14 to ground the sheet and all of its elements (the islands 22 and the mesh area 20) through the interconnecting portions of the sheet 14.”).
Coward and Mackie are both considered to be analogous to the claimed method because they are in the same field of additive manufacturing. Therefore, it would be obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the electrically conductive conducting mesh in Kelkar to incorporate grounding the electrically conductive conducting mesh as taught by Mackie in order to enhance higher speed, lower cost, and higher safety 3D printing (Mackie, [0009]).
Claims 6 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Coward (US 20190283982 A1), in view of Kelkar et al. (US 20190060998 A1; hereafter Kelkar) as applied in claim 1, and further in view of Larson (WO 2009027078 A1) and Ino et al. (US 20080080896 A1; hereafter Ino).
Regarding claim 6, Coward further teaches the second electrode having a variety of shapes ([0042], “the shape of electrode 21 can be different than that shown in FIG. 4.”), but does not teach the second electrode having a plurality of teeth and the powder particles comprise non-conductive powder particles.
However, Larson further teaches a method for applying powder particles unto a plate (Abstract), comprising a corona electrode (Page 3, line 4).
Coward and Larson are both considered to be analogous to the claimed method because they are pertinent to the problem of moving powder particles during solid fabrication process. Therefore, it would be obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the second electrode in Coward to incorporate a corona electrode as taught by Larson in order to generate a corona discharge (Larson, Page 7, line 29).
Modified Coward does not teach a corona electrode having a plurality of teeth.
However, Ino teaches a corona electrode having a plurality of teeth ([0006], “a saw-tooth electrode”)
Larson and Ino are both considered to be analogous to the claimed method because they are pertinent to the problem of using a corona electrode to provide electrostatic charge. Therefore, it would be obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the electrode in modified Coward to incorporate a corona electrode as taught by Larson, and incorporate a corona electrode having a plurality of teeth as taught by Ino, since a saw-tooth electrode is more advantageous than a wire electrode or the like in that it has a smaller number of components, has a longer life, generates a smaller amount of ozone, and has less failures such as breakage (Ino, [0006]).
Modified Coward does not teach that the powder particles comprise non-conductive powder particles. However, since “the powder particles” is considered intended use of a claimed apparatus, and the structure disclosed by modified Coward is capable of performing the claimed use, the additive manufacturing device in Coward teaches the elements in claim 6. See MPEP 2115.
Regarding claim 7, Coward further teaches the signal source comprises an AC signal source for applying an AC signal between the powder particle container and the corona electrode ([0030], Voltage supply 20 produces an alternating current electric potential; Fig. 2, voltage supply 20 supplies electric field between container 15 and electrode 21).
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 Vipul Malik whose telephone number is (571)272-0976. The examiner can normally be reached M-F.
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/VIPUL MALIK/Examiner, Art Unit 1754
/SEYED MASOUD MALEKZADEH/Primary Examiner, Art Unit 1754
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