DETAILED ACTION
Response to Amendment
The Amendment filed 03/13/2026 has been entered. Claims 1-6, 8-10, 12-25, and 27-38 remain pending in the application. Claims 16-20 and 32-36 have been withdrawn due to a restriction requirement. Claims 7, 11, and 26 have been canceled. New claims 37 and 38 have been added. Claims 1-6, 8-10, 12-15, 21-25, 27-31, and 37-38 are presented for examination on the merits. Applicant's amendments to the drawings have overcome the objections previously set forth in the Non-Final Rejection mailed 12/18/2025. Applicant's amendments to the specification have overcome the objections previously set forth in the Non-Final Rejection mailed 12/18/2025. Applicant's amendments to the claims have overcome the 112(b) rejections previously set forth in the Non-Final Rejection mailed 12/18/2025.
Claim Interpretation
The terms “jetting pulses” of claims 1, 5, and 8 and “power pulses” of claims 21 and 22 are interpreted interchangeably in view of the instant specification reciting “in response to the power pulses, the coils may generate jetting pulses”. One of ordinary skill in the art understands power pulses are needed to generate jetting pulses and consequently, the presence of a “jetting pulse” implies the presence of a “power pulse” and vice versa.
Claim Objections
Claims 1 and 21 are objected to because of the following informalities: claim 1 recites the limitation “ejected from the nozzle in response the jetting pulses after the amount of time” in line 11. This limitation has a possible typographical error and was possibly intended to recite “in response to the jetting pulses” (emphasis added). Similarly, claim 21 recites “in response the power pulses after the amount of time” instead of “in response to the power pulses” (emphasis added). Appropriate correction is required.
Claim Rejections - 35 USC § 112
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claims 9 and 24 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 9 recites the limitation “wherein the temperature is increased by an external heater positioned at least partially around the nozzle”. This limitation renders the claim indefinite. Claim 1, on which claim 9 depends, recites “wherein increasing the temperature of the build material comprises generating jetting pulses, wherein the jetting pulses heat the nozzle”. It is unclear whether the temperature increase of claim 9 is intended to replace the temperature increase by jetting pulses of claim 1, or if the external heater of claim 9 is intended to provide an additional temperature increase separate from the one generated by jetting pulses in claim 1.
Further regarding claim 9, if Applicant is intending to provide further heating in claim 9, it is further unclear how the build-up and build material can remain in the claimed sludgy state achieved by the temperature increase by jetting pulses of claim 1. One of ordinary skill in the art understands that increasing the temperature of a material in a “sludgy” state may result in the material transforming into a liquid.
Claim 24 recites the limitation “increasing the temperature of the metal alloy using a heating element to cause the metal alloy in the nozzle to transition back into the liquid state, wherein the temperature is increased using the heating element after the build-up and the metal alloy in the sludgy state are ejected from the nozzle”. This limitation renders the claim indefinite. Claim 21, on which claim 24 depends, recites “increasing the temperature of the metal alloy in the nozzle, which causes the metal alloy in the nozzle to transition from the solid state to a sludgy state, wherein increasing the temperature of the metal alloy comprises generating power pulses” and “wherein the build-up and the metal alloy in the sludgy state are ejected from the nozzle in response the power pulses after the amount of time”. It is unclear whether the temperature increase using a heating element of claim 24 is intended to replace the temperature increase by power pulses of claim 21, or if the heating element of claim 24 is intended to provide an additional temperature increase separate from the one generated by jetting pulses in claim 21.
Claims 9 and 24 are rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 9 recites the limitation “wherein the temperature is increased by an external heater positioned at least partially around the nozzle” (emphasis added). Claim 1, on which claim 9 depends, recites “wherein increasing the temperature of the build material comprises generating jetting pulses, wherein the jetting pulses heat the nozzle” (emphasis added). If the temperature increase by external heater of claim 9 is intended to replace the temperature increase by jetting pulses of claim 1 (see 112(b) rejection above), then claim 9 fails to include all the limitations of the claim upon which it depends.
Claim 24 recites the limitation “increasing the temperature of the metal alloy using a heating element to cause the metal alloy in the nozzle to transition back into the liquid state, wherein the temperature is increased using the heating element after the build-up and the metal alloy in the sludgy state are ejected from the nozzle”. Claim 21, on which claim 24 depends, recites “increasing the temperature of the metal alloy in the nozzle, which causes the metal alloy in the nozzle to transition from the solid state to a sludgy state, wherein increasing the temperature of the metal alloy comprises generating power pulses” (emphasis added) and “wherein the build-up and the metal alloy in the sludgy state are ejected from the nozzle in response the power pulses after the amount of time” (emphasis added). If the temperature increase using a heating element of claim 24 is intended to replace the temperature increase by power pulses of claim 21 (see 112(b) rejection above), then claim 24 fails to include all the limitations of the claim upon which it depends.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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 1-6, 8-10, 12-15, 21-25, 27-28 and 37-38 are rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0118258 A1 of Sachs (as cited in prior Office action), as applied to claims 1 and 4 above, in view of US 2017/0252821 A1 of Sachs (as cited in prior Office action, as cited in IDS mailed 09/27/2024 and hereby referred to as US’821).
Regarding claims 1 and 21, Sachs teaches nozzle servicing techniques for additive fabrication systems (Title). Sachs teaches 3D printing using metal containing multi phase materials is prone to nozzle clogging and flow artifacts and that these can be mitigated by monitoring process conditions and taking action at times based on other conditions (Abstract, 3D printing reads on claimed printing a 3D part). Sachs teaches an additive manufacturing system using heated extrusion and a metallic build material, where the extruder receives the build material from a source and advances it towards the opening of a nozzle for deposition on a build plate or other suitable surface ([0046]-[0048], reads on the claimed method for printing a 3D part, the method comprising ejecting a metal from a nozzle of a 3D printer). Sachs further teaches the build material is a metal containing multi-phase (MCMP) material and that the MCMP build material may be a metal alloy that exhibits a multi-phase equilibrium between at least one solid and at least one liquid phase ([0050], reads on the claimed metal alloy). One of ordinary skill in the art understands the ejected metal will cool and solidify to form the resulting 3D part, as seen in Fig. 3 of Sachs where the deposited metal is forming a solid part. A patent need not teach, and preferably omits, what is well known in the art. See MPEP § 2164.01.
Sachs therefore reads on the limitation a method for printing a 3D part of claims 1 and 21, the method comprising: ejecting a metal alloy from a nozzle of a 3D printer, wherein the metal alloy cools and solidifies after being ejected to form the 3D part of claim 21.
Regarding the temperature change steps of claims 1 and 21, Sachs teaches the nozzle servicing technique relies on reducing the nozzle temperature 2204 to a servicing temperature that is significantly below its operating temperature and often below the lower end of the working temperature range of the multi-phase build material ([0162], Fig. 22, 2204 reads on the claimed decreasing a temperature of the metal alloy in the nozzle). Sachs teaches after a dwell time at such a lower servicing temperature 2206, the nozzle is then heated back up to return it to the operating temperature 2208 and printing of the object may resume ([0162], 2208 reads on the claimed increasing the temperature of the metal alloy in the nozzle). Regarding the temperature decrease of claims 1 and 21, Sachs teaches preferably the temperature is brought well below the solidus temperature and that solidification or at least partial solidification is most beneficial (solidification reads on the claimed which causes the build material or metal alloy in the nozzle to transition from a liquid state to a solid state).
Sachs therefore reads on the limitation decreasing a temperature of a build material in a nozzle of a 3D printer which causes the build material in the nozzle to transition from a liquid state to a solid state of claim 1, and decreasing a temperature of the metal alloy in the nozzle which causes the metal alloy in the nozzle to transition from a liquid state to a solid state of claim 21.
Regarding the temperature increase of claims 1 and 21, Sachs teaches the metallic build material may be in a semi-solid state ([0050], semi-solid reads on the claimed sludgy state) and that the build material reaches a desired liquid fraction at the operating temperature ([0187], the material at the operating temperature would therefore be in a semi-solid or “sludgy” state). Sachs further teaches compositions within an alloy system with a eutectic, for example, may melt over a range of temperatures rather than at a melting point and thus provide a semi-solid state with a mixture of at least one solid and at least one liquid ([0051]-[0052], Fig. 4). As explained in Sachs and shown in Fig. 4, heating to a temperature above a melting point 406 achieves a semi-solid state with a liquid and solid phase between solidus curves 413a and 413b and liquidus curves 415a and 415b depending on the composition of the metallic build material.
Sachs therefore reads on the limitation increasing the temperature of the build material in the nozzle and cause the build material in the nozzle to transition from the solid state to a sludgy state of claim 1 and increasing the temperature of the metal alloy in the nozzle which causes the metal alloy in the nozzle to transition from the solid state to a sludgy state of claim 21.
Regarding the ejection of claims 1 and 21, Sachs teaches the volume reduction following partial or full solidification of the build material and the possible release of any dissolved gases may be sufficient to mechanically dislodge, free up or otherwise disturb any features that may have previously clogged, jammed or otherwise limited the flow of extrudate from the nozzle ([0163], reads on the claimed wherein a build-up and the build material or metal alloy in the sludgy state are ejected from the nozzle).
Sachs therefore reads on the limitation wherein a build-up and the build material in the sludgy state are ejected from the nozzle of claim 1 and wherein the build-up and the metal alloy in the sludgy state are ejected from the nozzle of claim 21.
Regarding the pulses of claims 1 and 21 and electromagnetic force of claim 21, Sachs teaches an additive manufacturing system that deposits a metal, metal alloy, or the like, using fused filament fabrication or any similar process ([0046]). Sachs teaches the nozzle servicing method is not limited to the illustrated embodiments set forth herein ([0041]). Sachs teaches absent an explicit indication to the contrary, the disclosed steps may be modified, supplemented, omitted, and/or re-ordered without departing from the scope of this disclosure and that numerous variations, additions, omissions, and other modifications will be apparent to one of ordinary skill in the art ([0215]).
Regarding the printing after build-up is ejected of claims 1 and 21, Sachs teaches a nozzle servicing technique which mechanically dislodges, frees up or otherwise disturb any features that may have previously clogged, jammed or otherwise limited the flow of extrudate from the nozzle ([0162]-[0163]). Sachs teaches printing of the object may resume after the nozzle servicing technique ([0162], reads on the claimed printing a 3D part with the build material).
Sachs therefore reads on the limitation printing a 3D part with the build material after the build-up and the build material in the sludgy state are ejected from the nozzle of claim 1 and printing a 3D part with the metal alloy after the build-up and the metal alloy in the sludgy state are ejected from the nozzle of claim 21.
Regarding the determining of build-up of claim 21, Sachs teaches a sensor, such as a load cell, torque sensor, camera, or optical sensor may be coupled to the drive system, to sense the load on the drive system to determine whether any blockages or other impediments to driving the build material may be occurring ([0090]-[0095], reads on the claimed determining that the build-up is present within the nozzle). Sachs teaches in response to sensing a blockage, the controller may take the appropriate action such as ceasing the extrusion of build material ([0095]). Sachs further teaches nozzle service may occur when an error condition is detected, in reaction to a process signal ([0112]).
Sachs therefore reads on the limitation determining that a build-up is present within the nozzle of claim 21.
However, Sachs does not explicitly disclose wherein increasing the temperature of the build material comprises generating jetting pulses to try to eject drops of the build material from the nozzle, wherein the drops are not ejected for an amount of time that the jetting pulses are generated, wherein the jetting pulses heat the nozzle of claim 1, wherein a build-up and the build material in the sludgy state are ejected from the nozzle in response the jetting pulses after the amount of time of claim 1, wherein increasing the temperature of the metal alloy comprises generating power pulses to try to eject drops of the metal alloy from the nozzle, wherein the drops are not ejected for an amount of time that the power pulses are generated of claim 21, wherein the build-up and the metal alloy in the sludgy state are ejected from the nozzle in response the power pulses after the amount of time of claim 21, and ejecting a metal alloy from a nozzle of a 3D printer using an electromagnetic force of claim 21.
US’821 teaches additive manufacturing of an object applying magnetohydrodynamic forces to liquid metal to eject liquid metal along a control pattern (Abstract). Sachs and US’821 is considered analogous art since it is similarly concerned with a method of 3D printing a part by ejecting a metal alloy through a nozzle.
US’821 teaches the additive manufacturing method includes any fluid containing metal alloys in liquid form ([0038], a fluid containing metal in liquid form is analogous to the semi-solid metallic material of Sachs since it contains a metal alloy wherein part of it is in liquid form). US’821 teaches magnetohydrodynamic forces can eject the liquid metal from the nozzle in a direction toward a build plate disposed within the build chamber ([0039], magnetohydrodynamic forces reads on the claimed electromagnetic force as further evidenced by the printer of US’821 including electrodes and magnets as described in [0041] or electromagnet of [0058]). US’821 teaches increasing the magnetic field present within the liquid metal can reduce the required magnitude and duration of the current pulses and is therefore desirable ([0058]). US’821 further teaches the magnetohydrodynamic force can be pulsed to eject droplets of the liquid metal to provide control over accuracy of the object being fabricated ([0004], [0039], pulsed magnetohydrodynamic forces reads on the claimed jetting pulses and power pulses since Sachs teaches the power source is pulsed to eject liquid metal in [0008] and [0043]). US’821 further teaches heaters can be in thermal communication with the liquid metal and that heating requirements associated with jetting droplets of the liquid metal will depend on the metal composition and sufficient heating can be obtained with only the MHD forces ([0056]-[0057], “the metal can be in liquid form at room temperature, such that MHD forces can be applied to the liquid metal without the use of the heater” implies heating requirements are met with the pulses only without the need of an additional heater).
Since Sachs teaches the nozzle servicing technique applies to any three-dimensional printers that deposit metal using techniques similar to fused filament fabrication, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the method of Sachs with the magnetohydrodynamic pulses of US’821 to provide control over accuracy of the object being fabricated, as taught by US’821.
Regarding the amount of time of claims 1 and 21, US’821 teaches the liquid metal can be ejected from the discharge region for a predetermined period of time ([0127]). US’821 further teaches the first electric current can be stopped a short period before delivery of the second electric current and during this short period, the oscillations induced in the meniscus by the first electric current can decay prior to ejection of a first droplet ejected in response to the second electric current ([0129], oscillations induced in a short period prior to ejection of a first droplet reads on the claimed to try to eject drops of material from the nozzle, wherein the drops are not ejected for an amount of time that the jetting pulses are generated; the first droplet ejected in response to the second electric current reads on the claimed wherein a build-up and the build material in the sludgy state are ejected from the nozzle in response to the jetting pulses after the amount of time). US’821 teaches the velocity of the liquid metal ejected from the discharge region can be controlled, for example, by changing one or more of magnitude and duration of the pulse ([106], modifying the pulse duration will implicitly modify the amount of time where pulses are generated).
Modified Sachs therefore reads on the limitation wherein increasing the temperature of the build material comprises generating jetting pulses to try to eject drops of the build material from the nozzle, wherein the drops are not ejected for an amount of time that the jetting pulses are generated, wherein the jetting pulses heat the nozzle of claim 1, wherein a build-up and the build material in the sludgy state are ejected from the nozzle in response the jetting pulses after the amount of time of claim 1, wherein increasing the temperature of the metal alloy comprises generating power pulses to try to eject drops of the metal alloy from the nozzle, wherein the drops are not ejected for an amount of time that the power pulses are generated of claim 21, wherein the build-up and the metal alloy in the sludgy state are ejected from the nozzle in response the power pulses after the amount of time of claim 21, and ejecting a metal alloy from a nozzle of a 3D printer using an electromagnetic force of claim 21.
Additionally, or alternatively since Sachs teaches using any 3D printing method similar to fused filament fabrication which is based on extrusion, it would have been obvious to one of ordinary skill in the art to modify Sach and use the electromagnetic force of US’821 because both 3D printing methods involve ejecting a metal with a liquid form through a nozzle to form an additively manufactured part. The claim would have been obvious because the substitution of one known element for another would have yielded predictable results to one of ordinary skill in the art before the effective filing date of the invention. See MPEP § 2143 I. B. In this case, one of ordinary skill in the art would reasonably expect the nozzle servicing method of Sachs to work with the magnetohydrodynamic 3D printing of US’821 since both 3D printing methods rely on the same principles of ejecting a material through a nozzle.
Regarding claim 2, modified Sachs teaches the method of claim 1 as described above.
Sachs teaches using a metal, metal alloy, metal composite, or the like, as a metallic build material ([0046], reads on the claimed metal alloy). Sachs further teaches one particularly desirable class of metallic build materials are metallic multi-phase materials, which can be any wholly or partially metallic mixture that exhibits a working temperature range in which at least one solid phase and at least one liquid phase co-exist, resulting in a rheology suitable for fused filament fabrication or similar techniques ([0048]).
Modified Sachs therefore reads on the limitation wherein the build material comprises a metal alloy of claim 2.
Regarding claim 3, modified Sachs teaches the method of claim 1 as described above.
Sachs teaches buildup of foreign phase materials such as oxides which can build up on a portion of the walls ([0106], oxide reads on the claimed metal oxide since Sachs uses a metallic build material). Sachs teaches the viscosity reduction of the servicing method may help dislodge and purge out flow restriction resulting from build-up solid particles as well as foreign species and oxides ([0154]). Sachs teaches the nozzle bore may take a wide array of geometries and cross-sections and need not be uniform along its length and may include diverging sections, converging sections, straight sections, and non-cylindrical sections ([0087]). Fig. 3 of Sachs shows a nozzle with a cylindrical nozzle bore and outlet and therefore one of ordinary skill in the art would reasonably expect the oxide buildup to form attached to the inside of the nozzle in the shape of the nozzle and therefore read on the claimed substantially annular ring which reduces an effective diameter of a bore through the nozzle.
Sachs therefore reads on the limitation wherein the build-up comprises a substantially annular ring including a metal oxide that is attached to an inner surface of the nozzle, which reduces an effective diameter of a bore through the nozzle of claim 3.
Regarding claim 4, modified Sachs teaches the method of claim 1 as described above.
Sachs teaches a sensor, such as a load cell, torque sensor, camera, or optical sensor may be coupled to the drive system, to sense the load on the drive system to determine whether any blockages or other impediments to driving the build material may be occurring ([0090]-[0095], reads on the claimed determining that the build-up is present within the nozzle). Sachs teaches in response to sensing a blockage, the controller may take the appropriate action such as ceasing the extrusion of build material ([0095]). Sachs further teaches nozzle service may occur when an error condition is detected, in reaction to a process signal ([0112]). Since nozzle service includes decreasing a temperature as described in the rejection of claim 1, Sachs teaches decreasing a temperature in response to determining a blockage is present.
Sachs therefore reads on the limitation further comprising determining that the build-up is present within the nozzle, wherein the temperature is decreased in response to determining that the build-up is present of claim 4.
Regarding claim 5, modified Sachs teaches the method of claim 1 as described above.
Sachs teaches before commencing the actual nozzle servicing step, the nozzle may optionally be moved away from the object build area, to the service area, so that the object is not fouled or damaged by the servicing routine and that printing may resume after the servicing technique ([0162], printing may resume reads on the claimed resuming generating the jetting pulses after ceasing to generate the jetting pulses since resuming printing will use the pulses of US’821 to eject the build material). Sachs teaches when a sensor indicates that a flow artifact is forming or has formed the controller may take the appropriate action such as ceasing the extrusion of build material ([0095], reads on the claimed ceasing in response to the determination that the build-up is present, which stops drops of the build material from being ejected from the nozzle). Sachs further teaches the description emphasizes three-dimensional printers that deposit metal, metal alloys, or other metallic compositions for forming a three-dimensional object using fused filament fabrication or similar techniques ([0210]).
Sachs therefore reads on the limitation further comprising: ceasing in response to the determination that the build-up is present, which stops drops of the build material from being ejected from the nozzle; and resuming generating the jetting pulses after ceasing to generate the jetting pulses of claim 5.
Regarding claim 6, Sachs teaches the method of claim 5 as described above.
Sachs teaches a sensor, such as a load cell, torque sensor, camera, or optical sensor may be coupled to the drive system, to sense the load on the drive system to determine whether any blockages or other impediments to driving the build material may be occurring ([0090]-[0095], reads on the claimed determining that the occlusion is present within the nozzle). Sachs teaches in response to sensing a blockage, the controller may take the appropriate action such as ceasing the extrusion of build material ([0095]). Sachs further teaches nozzle service may occur when an error condition is detected, in reaction to a process signal ([0112]). Sachs teaches before commencing the actual nozzle servicing step, the nozzle may optionally be moved away from the object build area to the service area so that the object is not fouled or damaged by the servicing routine ([0162]). Sachs teaches printing of the object may resume after the servicing routine ([0162]). Since the method of Sachs enacts a nozzle service when an error or blockage is detected, the step of moving the nozzle away from the build area reads on the claimed un-aligning the nozzle from a build plate after the occlusion has been determined to be present. One of ordinary skill in the art understands for the printing to resume, as taught by Sachs, the nozzle must be moved back to the build area to continue printing. A patent need not teach, and preferably omits, what is well known in the art. See MPEP § 2164.01.
Sachs therefore reads on the limitation further comprising: un-aligning the nozzle from a build plate after the occlusion has been determined to be present; and re-aligning the nozzle with the build plate after the temperature is increased of claim 6.
Regarding claim 8, modified Sachs teaches the method of claim 7 as described above.
Sachs teaches the volume reduction following partial or full solidification of the build material and the possible release of any dissolved gases may be sufficient to mechanically dislodge, free up or otherwise disturb any features that may have previously clogged, jammed or otherwise limited the flow of extrudate from the nozzle ([0163], reads on the claimed occlusion and the build material in the sludgy state to be ejected from the nozzle together).
Sachs teaches oxide buildup forms on the inner surface of the nozzle during the extrusion process and may form clogs ([0106]). One of ordinary skill in the art understands clogs reduce the effective diameter of a bore and that once the build-up is dislodged, the effective diameter of the nozzle will return to its original dimensions once free of the clog or buildup. Since the method of Sachs ejects clogs, the effective diameter of the nozzle will necessarily increase after the nozzle servicing routine results in a clog-free nozzle. The method of modified Sachs will use the jetting pulses of US’821 to eject the clog as taught by Sachs.
Modified Sachs therefore reads on the limitation wherein, in addition to increasing the temperature, the jetting pulses also cause the build-up and the build material in the sludgy state to be ejected from the nozzle together, thereby increasing an effective diameter of a bore through the nozzle of claim 8.
Regarding claim 9, modified Sachs teaches the method of claim 1 as described above.
Sachs teaches a heating system 306 may also or instead be configured to provide additional thermal control, such as by locally heating the build material 310 where it exits the nozzle 302 ([0085]-[0088], Fig. 3, heating system 306 reads on the claimed external heater; locally heating reads on the claimed wherein the temperature is increased; to locally heat the build material where it exits the nozzle the heating system must be positioned near the nozzle). Fig. 3 of Sachs shows the heating system 306 is positioned around nozzle bore 304 and therefore the heating system position reads on the claimed positioned at least partially around the nozzle.
Modified Sachs therefore reads on the limitation wherein the temperature is increased by an external heater positioned at least partially around the nozzle of claim 9.
Regarding claim 10, modified Sachs teaches the method of claim 1 as described above.
Sachs teaches an auxiliary heater (not shown) may be provided relatively close to the inlet 305, for times when it may be desired to add thermal power to the nozzle near to the inlet ([0088], 305 reads on the claimed heating element position upstream the nozzle). While the position of the auxiliary heater is described as relatively close, one of ordinary skill in the art understands the heater should be placed upstream from the nozzle since downstream is where the part is being built and therefore would not be a convenient place to install a heater.
Modified Sachs therefore reads on the limitation wherein the temperature is further increased by a heating element positioned upstream from the nozzle after the occlusion and the build material in the sludgy state are ejected from the nozzle of claim 10.
Regarding claims 12-15, modified Sachs teaches the method of claim 1 as described above.
Sachs teaches the nozzle servicing technique relies on reducing the nozzle temperature to a servicing temperature that is significantly below its operating temperature and often below the lower end of the working temperature range of the multi-phase build material, the nozzle is then heated back up to return it to the operating temperature and printing of the object may resume ([0162], printing may resume implies the process can be done before, after, or in the middle of a printing process and therefore between a first and second portion of the 3D printed part). Sachs further teaches an anticipatory nozzle service may be performed on a schedule based upon process quantities, such as but not limited to: mass of extrudate deposited, time elapsed, some function of the monitored extrusion force versus time or distance ([0114], anticipatory nozzle service performed on a schedule based on mass of extrudate deposited reads on the claimed wherein the temperature is decreased and then increased after a predetermined amount of the build material is ejected from the nozzle of claim 14, based on time elapsed reads on the claimed after a predetermined amount of time of ejecting the build material from the nozzle of claim 15).
Sachs therefore reads on the limitation wherein the temperature is decreased and then increased before the 3D part is printed or after the 3D part is printed of claim 12 and wherein the temperature is decreased and then increased after a first portion of the 3D part is printed and before a second portion of the 3D part is printed of claim 13, and wherein the temperature is decreased and then increased after a predetermined amount of the build material is ejected from the nozzle of claim 14, wherein the temperature is decreased and then increased after a predetermined amount of time of ejecting the build material from the nozzle of claim 15.
Regarding claim 22, modified Sachs teaches the method of claim 21 as described above.
Sachs does not explicitly disclose limitation further comprising transmitting power pulses to one or more coils, wherein pulses of the electromagnetic force are generated in the nozzle in response to the one or more coils receiving the power pulses, and wherein the temperature of the metal alloy in the nozzle increases in response to the pulses of the electromagnetic force
US’821 teaches using an electromagnet ([0058], one of ordinary skill in the art understands an electromagnet includes a coil). US’821 teaches a power source can be controlled to produce electric currents to eject the liquid metal through the use of MHD force ([0042]). Since Sachs teaches the magnetohydrodynamic force can be pulsed to eject droplets of the liquid metal, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the method of Sachs to include the coils and power source necessary to generate the magnetohydrodynamic forces of US’821 to provide control over accuracy of the object being fabricated, as taught by US’821. One of ordinary skill in the art understands that pulses increase the temperature of the droplets of liquid metal and therefore the pulses of US’821 read on the claimed wherein the temperature of the metal alloy in the nozzle increases in response to the pulses of the electromagnetic force.
Modified Sachs therefore reads on the limitation further comprising transmitting power pulses to one or more coils, wherein pulses of the electromagnetic force are generated in the nozzle in response to the one or more coils receiving the power pulses, and wherein the temperature of the metal alloy in the nozzle increases in response to the pulses of the electromagnetic force of claim 22.
Regarding claim 23, modified Sachs teaches the method of claim 22 as described above.
Sachs teaches the volume reduction following partial or full solidification of the build material and the possible release of any dissolved gases may be sufficient to mechanically dislodge, free up or otherwise disturb any features that may have previously clogged, jammed or otherwise limited the flow of extrudate from the nozzle ([0163], reads on the claimed also cause the occlusion and the metal alloy in the sludgy state to be ejected from the nozzle together). Sachs teaches oxide buildup forms on the inner surface of the nozzle during the extrusion process and may form clogs ([0106]). One of ordinary skill in the art understands clogs reduce the effective diameter of a bore and that once the buildup is dislodged, the effective diameter of the nozzle will return to its original dimensions once free of the clog or buildup. Since the method of Sachs ejects clogs, the effective diameter of the nozzle will necessarily increase after the nozzle servicing routine results in a clog-free nozzle.
Modified Sachs therefore reads on the limitation wherein, in addition to increasing the temperature, the pulses of the electromagnetic force also cause the build-up and the metal alloy in the sludgy state to be ejected from the nozzle together, thereby increasing an effective diameter of a bore through the nozzle of claim 23.
Regarding claim 24, modified Sachs teaches the method of claim 22 as described above.
Sachs teaches a heating system 306 may also or instead be configured to provide additional thermal control, such as by locally heating the build material 310 where it exits the nozzle 302 ([0085]-[0088], Fig. 3, heating system 306 reads on the claimed using a heating element to cause the metal alloy in the nozzle to transition back into the liquid state; locally heating reads on the claimed increasing the temperature of the metal alloy). Sachs further teaches a servicing temperature at or slightly above the temperature where the multi-phase metal alloy turns fully liquid may be especially beneficial ([0152]-[0153], reads on the claimed increasing the temperature of the metal alloy to transition back into the liquid state). Sachs further teaches anticipatory nozzle service may be performed on a schedule based upon process quantities and that nozzle service occurs before or between path segments ([0114]-[0115]). Sachs teaches printing of the object may resume after the nozzle servicing routine ([0162]).
Since Sachs teaches a heating system and resuming printing after the nozzle servicing routine, modified Sachs therefore reads on the limitation further comprising increasing the temperature of the metal alloy using a heating element to cause the metal alloy in the nozzle to transition back into the liquid state, wherein the temperature is increased using the heating element after the occlusion and the metal alloy in the sludgy state are ejected from the nozzle of claim 24.
Regarding claims 25 and 27-28, modified Sachs teaches the method of claim 21 as described above.
Sachs teaches an anticipatory nozzle service may be performed on a schedule based upon process quantities, such as but not limited to: mass of extrudate deposited, time elapsed, some function of the monitored extrusion force versus time or distance or number of path segments printed ([0114], a mass of extrudate necessarily includes a certain number of drops and is merely a different form to measure an amount of material extruded, therefore the mass of extrudate also reads on the claimed mass or a volume of the predetermined number of drops of claim 27 and predetermined number of drops of claim 28). Sachs further teaches the nozzle service scheduled can be programmed to track any process information relevant to service scheduling, such as length of a period of time, distance or mass or volume of extruded material, using a service criterion ([0114]). Sachs teaches ideally, nozzle service occurs before, or between path segments and not during a path segment ([0115]). Sachs further teaches process conditions include extrusion force, optically observed condition of build material as extruded, elapsed extrusion time, distance of material deposited, mass of material deposited, volume of material deposited, number of segments deposited, number of layers deposited, average of any of the foregoing, moving average of any of the foregoing, and exponentially weighted moving average of any of the foregoing ([0007], optically observed condition of build material as extruded and distance of material deposited reads on the claimed measuring a height of the 3D part of claim 25).
Regarding the threshold of claims 25 and 27-28, Sachs teaches the controller queries whether any service criterion counter is over its threshold and the system continues to deposit material if not ([0114]). Sachs further teaches the system performs a nozzle service after the completion of the current path segment if any service criterion counter is over its threshold ([0114], reads on the claimed determining that the height is less than a predetermined height threshold of claim 25, determining that a mass or a volume of the predetermined number of drops of the metal alloy is less than a predetermined threshold of claim 27, determining that a mass or a volume of the predetermined number of drops of the metal alloy ejected at the first time is greater than the mass or the volume of the predetermined number of drops of the metal alloy ejected at the second time by more than a predetermined threshold of claim 28).
Regarding the times of claim 28, since Sachs teaches nozzle service may occur between path segments ([0115]), the method of Sachs reads on the claimed ejecting a predetermined number of drops of the metal alloy from the nozzle at a first time; ejecting the predetermined number of drops of the metal alloy from the nozzle at a second time. Sachs teaches monitoring aspects of deposition, such as visually monitoring aspects of the build material, as discussed, and any other deposition quality monitoring modes may also occur during all deposition steps ([0117], all deposition steps reads on the claimed ejecting a predetermined number of drops of the metal alloy from the nozzle at a first time of claim 28). Sachs teaches, for example, if a clog may manifest over the course of 10 ms, then a sample rate of at least 10 ms and preferably 5 ms and more preferably 2 ms may be used to monitor for clog formation in the nozzle ([0117]).
Continuously monitoring at a sample rate of at least 10 ms will result in a time of one minute or more in between two different deposition steps and therefore the monitoring of Sachs reads on the claimed wherein the first time and the second time are separated by one minute or more of claim 28.
Additionally, or alternatively, since Sachs teaches time elapsed is one of the process conditions monitored and adjusted for nozzle services, the time elapsed between printed segments being one minute or more is a variable that is within what one of ordinary skill in the art can adjust depending on the conditions and desired results of the 3D printing process.
Modified Sachs therefore reads on the limitation wherein determining that the build-up is present within the nozzle comprises: measuring a height of the 3D part; and determining that the height is less than a predetermined height threshold of claim 25, wherein determining that the build-up is present within the nozzle comprises: ejecting a predetermined number of drops of the metal alloy from the nozzle; and determining that a mass or a volume of the predetermined number of drops of the metal alloy is less than a predetermined threshold of claim 27, and wherein determining that the build-up is present within the nozzle comprises: ejecting a predetermined number of drops of the metal alloy from the nozzle at a first time; ejecting the predetermined number of drops of the metal alloy from the nozzle at a second time, wherein the first time and the second time are separated by one minute or more; and determining that a mass or a volume of the predetermined number of drops of the metal alloy ejected at the first time is greater than the mass or the volume of the predetermined number of drops of the metal alloy ejected at the second time by more than a predetermined threshold of claim 28.
Regarding the amount of time of claims 37 and 38, modified Sachs teaches the method of claim 1 as described above.
Sachs teaches, for example, if a clog may manifest over the course of 10 ms, then a sample rate of at least 10 ms and preferably 5 ms and more preferably 2 ms may be used to monitor for clog formation in the nozzle ([0117]). Sachs further teaches idle or dwell time during the stoppage may be preferably 10 ms, 100 ms, 1 s or 10 s and may vary depending on the particular process and deceleration capabilities of the robotics ([0150], idle time is analogous to the amount of time before ejecting the material).
US’821 teaches the liquid metal can be ejected from the discharge region for a predetermined period of time ([0127]). US’821 further teaches the first electric current can be stopped a short period before delivery of the second electric current and during this short period, the oscillations induced in the meniscus by the first electric current can decay prior to ejection of a first droplet ejected in response to the second electric current ([0129], oscillations induced in a short period prior to ejection of a first droplet reads on the claimed to try to eject drops of material from the nozzle, wherein the drops are not ejected for an amount of time that the jetting pulses are generated). US’821 teaches the velocity of the liquid metal ejected from the discharge region can be controlled, for example, by changing one or more of magnitude and duration of the pulse ([106], modifying the pulse duration will implicitly modify the amount of time where pulses are generated).
US’821 teaches the frequency of the pulsed current may be less than about 5 kHz at a maximum speed ([0009], [0049], a frequency of 5 kHz corresponds to a period of 0.2 ms and therefore encompasses a time of 0.2 ms or greater).
In the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I. In this case, both Sachs and US’821 teach amounts of time with ranges overlapping with the claimed range.
Since Sachs teaches having the material in a solid state before increasing the material temperature to eject the build-up, the amount of time of modified Sachs will overlap with when the build materials is in the solid state of Sachs.
Modified Sachs reads on the limitation wherein the amount of time is from about 1 second to about 3 minutes of claim 37 and wherein the amount of time is while the build material is in the solid state of claim 38.
Claims 29-31 are rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0118258 A1 of Sachs (as cited in prior Office action) in view of US 2017/0252821 A1 of Sachs (as cited in prior Office action, as cited in IDS mailed 09/27/2024, and hereby referred to as US’821), as applied to claim 21 above, and further in view of US 2021/0379664 A1 of Gibson (as cited in prior Office action, as cited in IDS mailed 09/27/2024).
Regarding claim 29, modified Sachs teaches the method of claim 21 as described above.
Sachs teaches a sensor, such as a load cell, torque sensor, camera, or optical sensor may be coupled to the drive system, to sense the load on the drive system to determine whether any blockages or other impediments to driving the build material may be occurring ([0090]-[0095], reads on the claimed determining that the occlusion is present within the nozzle). Sachs teaches in response to sensing a blockage, the controller may take the appropriate action such as ceasing the extrusion of build material ([0095]). Sachs further teaches nozzle service may occur when an error condition is detected, in reaction to a process signal ([0112]). Sachs teaches the controller queries whether any service criterion counter is over its threshold and the system continues to deposit material if not ([0114]). Sachs further teaches the system performs a nozzle service after the completion of the current path segment if any service criterion counter is over its threshold ([0114], threshold reads on the claimed threshold of claims 30-31). Sachs further teaches an anticipatory nozzle service may be performed on a schedule based upon process quantities, such as but not limited to: mass of extrudate deposited ([0114]).
However, modified Sachs does not explicitly disclose wherein determining that the occlusion is present within the nozzle comprises detecting satellites of the metal alloy around the 3D part, and wherein a mass of each satellite is less than 50% of a mass of a drop of the metal alloy without the build-up present.
Gibson teaches an improved additive manufacturing system for manufacturing metal parts by magnetohydrodynamic printing liquid metal (Abstract). Sachs, US’821 and Gibson are considered analogous art since they are all similarly concerned with a method of 3D printing a part by ejecting a metal alloy through a nozzle. Sachs and Gibson are similarly concerned with solving the problem of monitoring printing conditions to enact cleaning the nozzle.
Gibson teaches if the droplets are jetted from a nozzle, there are several conditions which may cause the droplets to land in other than an intended location including a change in the angle or velocity of the droplet(s) exiting the nozzle, change in the size of droplets, production of “satellites” (unwanted additional drops generated during jetting), or clogging or other stopping of the jetting altogether, which can produce an unwanted reduction in the quality of the printed output ([0005], angle reads on the claimed measure angle to vertical of claim 30 and velocity reads on the claimed speed of claim 31). Gibson further teaches unwanted “satellites” or secondary drops are detected by the presence of multiple drops at the same distance along the jetting direction, drops at extreme angles, or very large differences between velocities between drops ([0066], satellites read on the claimed satellites of the metal alloy around the 3D part of claim 29). Gibson teaches satellites are detected by the presence of multiple drops at the same distance and that if angles deviate from each other by more than a small amount, multiple streams are present ([0066]). Gibson further teaches that a print job is aborted altogether if parameters deviate too far from specification ([0067]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify the method of modified Sachs to include the monitoring of satellites, angle, and speed changes of Gibson to detect and address issues producing an unwanted reduction in the quality of the printed output, as taught by Gibson. Since Gibson limits the angle deviation to “more than a small amount” and that a print job is aborted is parameters deviate “too far”, one of ordinary skill in the art understands the satellites would be detected when they are small and therefore read on the claimed wherein a mass of each satellite is less than 50% of a mass of a drop of the metal alloy of claim 29.
Additionally, or alternatively, the optimization of a result effective parameter is considered within the skill of the artisan. See, In re Boesch and Slaney (CCPA) 204 USPQ 215. This is what research chemists do, optimization of result-effective variables through routine experimentation (MPEP 2144.05 IIA and B).
While Gibson does not explicitly disclose wherein a mass of each satellite is less than 50% of a mass of a drop of the metal alloy of claim 29, it is well within the abilities of an ordinary artisan to optimize the amount of material in a satellite depending on the desired outcome and quality of the final product. As such, one of ordinary skill in the art would have arrived at the instantly claimed range of a mass of each satellite is less than 50% of a mass of a drop of the metal alloy through no more than routine experimentation. Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[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).
Modified Sachs therefore reads on the limitation wherein determining that the build-up is present within the nozzle comprises detecting satellites of the metal alloy around the 3D part, and wherein a mass of each satellite is less than 50% of a mass of a drop of the metal alloy of claim 29, wherein determining that the occlusion is present within the nozzle comprises: measuring an angle at which the metal alloy is ejected from the nozzle; and comparing the measured angle to vertical, wherein the occlusion is determined to be present in response to a difference between the measured angle and vertical being greater than a predetermined angle threshold of claim 30, and wherein determining that the build-up is present within the nozzle comprises determining that a speed at which drops of the metal alloy are ejected from the nozzle is below a predetermined speed threshold of claim 31.
Response to Arguments
Applicant’s arguments with respect to claims 1-15 and 21-28 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. In particular, the 35 U.S.C. 103 rejections in this Office action rely on US’821 for the teaching of jetting pulses and not Sachs ‘258 as argued by Applicant.
Applicant argues that Sachs ‘258 does not disclose jetting pulses (remarks, page 13). Applicant argues that Sachs ‘821 does not remedy the deficiencies of Sachs ‘258 (remarks, page 14). Applicant argues that Gibson does not remedy the deficiencies of Sachs ‘258 and Sachs ‘258 (remarks, page 14).
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 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). In this case, claim 1 did not contain the claimed jetting pulses before the amendment of 03/13/2026. The jetting pulses were previously included in claim 5 and the 35 U.S.C. 103 rejection previously set forth in the Non-Final Rejection mailed 12/18/2025 relied on the teachings of US’821 for the jetting pulses and not Sachs ‘258. See 35 U.S.C. 103 rejections herein for the updated rejection to address amended claim set filed on 03/13/2026.
Applicant's arguments do not comply with 37 CFR 1.111(c) because they do not clearly point out the patentable novelty which he or she thinks the claims present in view of the state of the art disclosed by the references cited or the objections made. Further, they do not show how the amendments avoid such references or objections.
In this case, Applicant is encouraged to show specific citations in the prior art which distinguish the prior art combination from the instant claims.
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 extension fee 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 date of this final action.
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/M.A./Examiner, Art Unit 1733
/REBECCA JANSSEN/Primary Examiner, Art Unit 1733
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