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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on November 12, 2025 has been entered.
Priority
Acknowledgment is made of applicant’s claim for foreign priority (DE102019132349.5, filed on 28 November 2019) under 35 U.S.C. 119 (a)-(d). Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Objections
Claim 55 objected to because of the following informalities:
The phrase “in which enclosure the metal printing is carried out” should be corrected to read “in which the metal printing is carried out in the enclosure” to improve clarity.
The phrase “wherein in a shutoff state the shutoff valve of the medium inlet…” should be corrected to read “wherein, in a shutoff state, the shutoff valve of the medium inlet…” to improve clarity.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION. —The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 57–58, 61–64, 67–69, and 74–82 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 55 recites the limitation “shut off to produce a negative pressure.” It is unclear how shutting off the medium inlet and the medium outlet produces a negative pressure in the interior of the filter housing, such that the scope of the claim is unclear. For example, clarifying the claim to specify that the negative pressure is produced by providing a vacuum to build up the negative pressure, as recited in Claim 58, may resolve this ambiguity. Claims 57–58, 61–64, 67–69, and 74–82, which depend from Claim 55, are similarly rejected by virtue of dependency.
Claim 55 recites the limitation “a discharge valve…shutting off the filtered material collecting chamber.” It is unclear what passage, opening, or flow path is shut off by the discharge valve to shut off the filtered material collecting chamber, such that the scope of the claim is unclear. Claims 57–58, 61–64, 67–69, and 74–82, which depend from Claim 55, are similarly rejected by virtue of dependency.
Claim 57 recites the limitation “can be carried out by a reduction of the negative pressure.” It is unclear what “reduction of the negative pressure” means and what structure or operation performs the reduction to introduce the flushing medium into the filter housing, such that the scope of the claim is unclear.
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.
Claim 60 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 60 recites “a discharge valve is provided between the filtered material collecting chamber and the filter” and “configured for shutting off the filtered material collecting chamber.” However, Claim 56 already recites “a shutoff valve, the shutoff valve being configured for shutting off the filtered material collecting chamber,” such that Claim 60 does not constitute a further limitation of Claim 56, but merely restates the shutoff function for the filtered material collecting chamber.
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
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 55, 57-59, 61, 67, 68, 76-81 are rejected under 35 U.S.C. 103 as being unpatentable over WITTER et al. (US20140223690A1, hereinafter WITTER) in view of SUTCLIFFE et al. (US20180244034A1, hereinafter SUTCLIFFE) and KROEMMER et al. (US20030075085A1, hereinafter KROEMMER).
Regarding Claim 55, WITTER discloses a heavy-duty vacuum cleaner intended for workshop and industrial use, where the device operates as a high-capacity hybrid vacuum/dust collector with multiple dust separation stages, including cyclonic pre-separation and final filtration (¶¶[0002]–[0003]).
FIG. 1 illustrates the exterior of the cyclonic vacuum cleaner (10), which is built around a cone-shaped housing (12) with an intake pipe (16) positioned along its midsection. The intake pipe is connected to a vacuum hose (14), and a gate valve (84) is installed in the intake pipe to allow the intake to be closed, thereby enabling the interior of the housing to be shut off for pulse-cleaning operations (¶[0038]).
FIG. 2 illustrates a conic housing divided into a lower cyclonic chamber (32) and an upper filter chamber (38), separated by a horizontal separator plate (34). Dust-laden air enters the cyclonic chamber through an intake pipe (16), flows along the conic wall, and moves upward through a vortex tube (36) into the filter chamber. A cylindrical cartridge filter (44) is positioned in the filter chamber, where air flows radially through filter media (46) into an open core (48) for final filtration (¶¶[0041]–[0043]).
The lower end of the housing connects to a dust collection drum (22) via a flange (18) and a drum lid (20), which together form a sealed, dust-tight joint. The drum is mounted on a wheeled carriage (24) and can be detached for emptying (¶[0039]). Collected dust is contained in a flexible film bag liner inside the drum, secured by a hold-down feature such as a vacuum conduit. The lid is removed to access the liner, allowing for disposal of the collected material (¶¶[0027]–[0028]).
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FIGs. 1 and 2 of WITTER et al.
However, WITTER does not explicitly disclose “the medium outlet comprises a shutoff valve,” “the shutoff valve having an open position and a closed position,” and “shut off to produce a negative pressure.”
SUTCLIFFE discloses an additive manufacturing apparatus that includes a build chamber, a gas flow circuit for generating a gas flow through the build chamber, and a pair of filter assemblies arranged in parallel within the gas flow circuit (¶[0007]).
The filter assembly is arranged in the gas flow circuit, with each filter assembly having an associated upstream valve operable to seal the circuit before the assembly and a downstream valve operable to seal the circuit after the assembly (i.e., valves having open and closed positions), allowing filter element change while maintaining a controlled build chamber atmosphere, and further comprising a purging device configured to purge air from the sealed filter assembly (¶[0012]).
The apparatus further comprises a purging device arranged to apply low pressure or vacuum to each filter assembly to remove air, with a controller configured to purge the filter assembly before reopening the associated valves, and capable of purging one parallel filter assembly while the other remains connected to filter particulates from the gas flow (¶¶[0014]–[0016]).
Advantageously, SUTCLIFFE addresses air ingress risks during filter replacement or door opening that can reoxygenate the build chamber or ignite reactive particles, by providing upstream and downstream shutoff valves to isolate the filter housing and a purging device configured to apply low pressure or vacuum to remove air and produce negative pressure in the shutoff state for safe air removal (¶¶[0005]–[0006], ¶[0012], ¶¶[0014]–[0016]). In view of WITTER’s intake closure to isolate the housing for pulse cleaning, one of ordinary skill in the art would have been motivated to incorporate SUTCLIFFE’s downstream shutoff valve and vacuum purging capability to fully seal the filter housing in a shutoff state, produce negative pressure therein for air removal, and prevent oxygen ingress that risks reoxygenating the system or igniting reactive particulates.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate the downstream shutoff valve and negative pressure production capability into the vacuum filtration system by WITTER.
However, modified WITTER does not explicitly disclose “a discharge valve disposed between the filtered material collecting chamber and the filter.”
Discharge valves are well known in dust collection systems for controlling discharge of collected particulate. In this context, KROEMMER discloses a dust discharge system comprising a dust discharge valve located downstream of a dust discharge opening and a fully enclosed conveying system connected downstream of the valve (¶[0010]).
FIG. 1 illustrates a cone-bottom dust catcher (14) connected to a dust discharge opening (16) equipped with a discharge valve (18). The valve outlet is connected by a conduit (20) to an enclosed mechanical conveyor (22) comprising a motor (24) that drives paddles (26) through a sealed duct (28) to transport dust into a recipient (29). A control system (32) monitors the electrical load of the conveyor and automatically regulates the valve (18). The valve closes when the load exceeds a preset threshold and opens when the load drops below that value. Level probes (36, 38) in the cone bottom initiate and terminate the discharge cycle based on the amount of accumulated dust (¶¶[0025]–[0026]).
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FIG. 1 from KROEMMER
Advantageously, the discharge valve and control system disclosed by KROEMMER prevent clogging of the downstream conveying system, increase average discharge capacity and efficiency, reduce the frequency of breakdowns and maintenance, and minimize the risk of gas breakthrough (¶[0010]). In view of modified WITTER’s dust collection drum arrangement, a person skilled in the art would incorporate KROEMMER’s discharge valve and control system between modified WITTER’s filter housing and the collection drum to improve controlled discharge of collected dust while reducing clogging and maintenance.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate the discharge valve and control system positioned between the filter housing and the collection drum, as disclosed by KROEMMER, into the vacuum filtration system by modified WITTER.
Regarding Claim 57, modified WITTER makes obvious the vacuum filtration system of Claim 55. WITTER discloses in a cleaning operation, the pulse plate is lifted by the pulsing handle, allowing ambient air, as the medium, to flow into the open core of the filter and exit outward through the filter media 46, thereby blasting accumulated dust from the outer surface (¶[0060]).
Regarding Claim 58, modified WITTER makes obvious the vacuum filtration system of Claim 55. WITTER discloses a blower vac unit (50), formed as a centrifugal air pump, mounted above the motor plate (40) and connected by an intake duct (52) that extends into the outlet opening. The blower generates suction to create negative pressure during operation (FIG. 2, ¶[0044]).
Regarding Claim 59, modified WITTER makes obvious the vacuum filtration system of Claim 58. WITTER discloses that the dust collection drum 22 is sealed to the filter housing by a drum lid 20 and flange 18, forming a continuous airtight connection (FIG. 2, ¶[0039]). It is reasonably interpreted that the sealed interface permits the filter housing and the collecting chamber to be subjected to negative pressure during operation.
Regarding Claim 61, modified WITTER makes obvious the vacuum filtration system of Claim 55. WITTER discloses a dust collection drum (22) that is mounted on a wheeled carriage (24) and joined to the filter housing by a detachable lid (20), forming a sealed, dust-tight interface (¶[0039]). It is reasonably interpreted that the use of a carriage and detachable lid indicates the drum is removable from the housing for emptying.
Regarding Claim 62, modified WITTER makes obvious the vacuum filtration system of Claim 59. KROEMMER discloses a dust discharge system comprising a dust discharge valve located downstream of a dust discharge opening (¶[0010]). The valve is regulated between open and closed states to control discharge (¶¶[0025]–[0026]). It is reasonably interpreted that KROEMMER’s regulated discharge valve provides a shutoff function for the collecting chamber’s discharge path, such that a shutoff valve is provided for closing the filtered material collecting chamber.
Regarding Claim 63, modified WITTER makes obvious the vacuum filtration system of Claim 62. KROEMMER discloses that the discharge valve is regulated between open and closed states (¶¶[0025]–[0026]). It is reasonably interpreted that, during normal operation with the collecting chamber arranged on the filter housing, the discharge valve is in an open position to permit discharge flow through the collecting chamber’s discharge path.
Regarding Claim 67, modified WITTER makes obvious the vacuum filtration system of Claim 55. WITTER discloses a pulse-cleaning operation where ambient air is introduced into the filter housing (¶[0060]). The dislodged dust falls into a collection drum through a vortex path. It is reasonably interpreted that, after the cleaning medium is introduced, the system returns to normal vacuum operation such that access for feeding filtered material into the filtered material collecting chamber is provided by the intake flow path.
Regarding Claim 68, modified WITTER makes obvious the vacuum filtration system of Claim 67. WITTER discloses a vacuum filtration system, and its operation necessarily involves suction during normal use. It is reasonably interpreted that feeding the filtered material into the filtered material collecting chamber by suction is met by the vacuum operation of WITTER.
Regarding Claims 76–80, modified WITTER makes obvious the vacuum filtration system of Claim 55. SUTCLIFFE discloses that the purging device is arranged to apply a vacuum or low pressure to each filter assembly, and a controller is configured to purge a given filter assembly before opening its valves. One of the parallel filter assemblies can be flushed while the other remains connected to filter particulates from the gas flow (¶¶[0014]–[0016]).
FIGs. 4a and 4b illustrate a purging system (210) connected to a gas flow circuit comprising two filter assemblies (200, 201) arranged in parallel. Each filter assembly includes a filter housing (202, 203), a filter element (E-5, E-7), and valves (V-2, V-3, V-6, V-7) for controlling inlet and outlet flow, enabling one assembly to be shut off and removed while the other remains active. The purging system (210) comprises a separate inert gas reservoir (211) configured to flush the shut-off filter assembly. Inert gas is introduced downstream of the filter assembly under control of solenoid valves (V-12, V-13), and vented via a separate vent line (206) controlled by valves (V-10, V-11), with oxygen levels monitored by a sensor (I-1) (¶¶[0053]–[0055]).
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FIGS. 4a and 4b from SUTCLIFFE et al.
FIG 4a illustrates a normal operation with gas flow directed through the left-side filter assembly, while FIG 4b shows a filter replacement configuration in which the left-side filter is shut off and gas flow is redirected through the right-side filter assembly.
Regarding Claim 81, modified WITTER makes obvious the vacuum filtration system of Claim 76. WITTER discloses a cyclonic chamber (32) formed in the lower half of the conic housing, into which air enters via the intake pipe (16), spirals around the inner wall, and proceeds upward through a vortex tube (36) into a filter chamber (38) positioned above (¶[0041]). The cyclonic chamber separates heavier particulates before they reach the filter, operating as a pre-separator upstream of the filter device in the direction of flow.
Claims 56, 60, 66, 70 and 83 are rejected under 35 U.S.C. 103 as being unpatentable over WITTER et al. (US20140223690A1, hereinafter WITTER) in view of KROEMMER et al. (US20030075085A1, hereinafter KROEMMER).
Regarding Claim 56 and 60, WITTER discloses a heavy-duty vacuum cleaner intended for workshop and industrial use, where the device operates as a high-capacity hybrid vacuum dust collector with multiple dust separation stages, including cyclonic pre-separation and final filtration (¶¶[0002]–[0003]).
FIG. 1 illustrates the exterior of the cyclonic vacuum cleaner (10), which is built around a cone-shaped housing (12) with an intake pipe (16) positioned along its midsection. The intake pipe is connected to a vacuum hose (14), and a gate valve (84) is installed in the intake pipe to allow the intake to be closed, thereby enabling the interior of the housing to be shut off for pulse-cleaning operations (¶[0038]).
FIG. 2 illustrates a conic housing divided into a lower cyclonic chamber (32) and an upper filter chamber (38), separated by a horizontal separator plate (34). Dust-laden air enters the cyclonic chamber through an intake pipe (16), flows along the conic wall, and moves upward through a vortex tube (36) into the filter chamber. A cylindrical cartridge filter (44) is positioned in the filter chamber, where air flows radially through filter media (46) into an open core (48) for final filtration (¶¶[0041]–[0043]).
The lower end of the housing connects to a dust collection drum (22) via a flange (18) and a drum lid (20), which together form a sealed, dust-tight joint. The drum is mounted on a wheeled carriage (24) and can be detached for emptying (¶[0039]). Collected dust is contained in a flexible film bag liner inside the drum, secured by a hold-down feature such as a vacuum conduit. The lid is removed to access the liner, allowing for disposal of the collected material (¶¶[0027]–[0028]).
A pulse-cleaning system comprising a pulse plate (74), an annular opening (76), and a pulsing handle (30) is positioned above the open core (48) of the filter and integrated with the motor plate assembly. The plate covers the annular opening and is normally sealed by vacuum (¶[0050]). In a cleaning operation, the pulse plate is lifted by the pulsing handle, and ambient air flows into the open core of the filter and exits outward through the filter media (46), thereby blasting accumulated dust from the outer surface (¶[0060]).
However, WITTER does not explicitly disclose “a discharge valve disposed between the filtered material collecting chamber and the filter.”
KROEMMER discloses a dust discharge system comprising a dust discharge valve located downstream of a dust discharge opening and a fully enclosed conveying system connected downstream of the valve (¶[0010]).
FIG. 1 illustrates a cone-bottom dust catcher (14) connected to a dust discharge opening (16) equipped with a discharge valve (18). The valve outlet is connected by a conduit (20) to an enclosed mechanical conveyor (22) comprising a motor (24) that drives paddles (26) through a sealed duct (28) to transport dust into a recipient (29). A control system (32) monitors the electrical load of the conveyor and automatically regulates the valve (18). The valve closes when the load exceeds a preset threshold and opens when the load drops below that value. Level probes (36, 38) in the cone bottom initiate and terminate the discharge cycle based on the amount of accumulated dust (¶¶[0025]–[0026]).
Advantageously, the discharge valve and control system disclosed by KROEMMER prevent clogging of the downstream conveying system, increase average discharge capacity and efficiency, reduce the frequency of breakdowns and maintenance, and minimize the risk of gas breakthrough (¶[0010]). In view of WITTER’s dust collection drum arrangement, a person skilled in the art would incorporate KROEMMER’s discharge valve and control system between WITTER’s filter housing and the collection drum to improve controlled discharge of collected dust while reducing clogging and maintenance.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate the discharge valve and control system positioned between the filter housing and the collection drum, as disclosed by KROEMMER, into the vacuum filtration system by WITTER.
Regarding Claim 66, modified WITTER makes obvious the vacuum filtration system of Claim 56. WITTER discloses that in a cleaning operation, the pulse plate is lifted by the pulsing handle, allowing ambient air to flow into the open core of the filter and exit outward through the filter media (46), thereby blasting accumulated dust from the outer surface (¶[0060]). It is reasonably interpreted that the flushing medium flows onto the side representing an outer surface of the filter wall in the filter operation.
Regarding Claim 70, modified WITTER makes obvious the vacuum filtration system of Claim 56. WITTER discloses a pulse plate (74), formed as an annular disk, seated above an annular opening (76) in the motor plate (40). The annular opening consists of multiple penetrations surrounding the central outlet (54) and permits ambient air to enter the filter core during pulsing (¶[0050]). Since the annular opening is formed from a ring of discrete holes, this can reasonably be interpreted as multiple individual flushing medium inlets, each capable of bursting air in different directions across the filter wall. It is reasonably interpreted that the multiple individual flushing medium inlets include one configured to direct the flushing medium to pass through the filter wall in a direction opposite to the filter operation, and one configured to direct the flushing medium onto an outer surface of the filter wall.
Regarding Claim 83, modified WITTER makes obvious the vacuum filtration system of Claim 56. WITTER discloses a blower vac unit (50), which is a centrifugal air pump oriented along the axis of the unit and mounted above the filter (¶[0044]).
Claim 64 is rejected under 35 U.S.C. 103 as being unpatentable over WITTER in view of SUTCLIFFE and KROEMMER as applied to claim 62 above, and further in view of VOKES (US2544244).
Regarding Claim 64, modified WITTER makes obvious the vacuum filtration system of Claim 62. However, modified WITTER does not explicitly disclose “upon removal of the filtered material collecting chamber from the filter housing, the shutoff valve is displaced in a spring-supported manner into a closed position.”
VOKES discloses a filter designed to maintain uninterrupted fluid flow during maintenance, particularly in oil supply systems for engine bearings. A valve in the filter head directs fluid through the filter element during normal operation, and the filter allows the element to be removed for servicing without interrupting fluid flow (Col. 1, Lns. 1–9).
The system further includes a helical spring and guide pins associated with the valve body, where the spring biases the valve body and the guide pins prevent valve rotation and ensure alignment (Col. 2, Lns. 16–20). Upon removal of the drain plug, the spring closes the valve, sealing passages to and from the filter while opening a direct inlet outlet connection, and the securing bolt may then be withdrawn to allow removal of the filter pot and access to the element without disrupting system operation (Col. 2, Lns. 46–53).
Advantageously, VOKES aims to ensure that the filter element can be removed for servicing or cleaning without disrupting the fluid flow through the system (Col. 1, Lns. 6–9). In view of modified WITTER’s vacuum filtration system with a removable collecting chamber, a person skilled in the art would incorporate VOKES’s spring biased shutoff valve so that the valve closes when the collecting chamber is removed.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate the spring-biased shutoff valve disclosed by VOKES into the vacuum filtration system by modified WITTER.
Claim 69 is rejected under 35 U.S.C. 103 as being unpatentable over WITTER in view of SUTCLIFFE and KROEMMER as applied to claim 55 above, and further in view of MAKARTCHOUK et al. (US20110252765A1, hereinafter MAKARTCHOUK).
Regarding Claim 69, modified WITTER makes obvious the vacuum filtration system of Claim 55. WITTER discloses that the air flows radially inward through a cylindrical filter media (46) surrounding an open core (48) and proceeds upward through the outlet opening in the motor plate (40) (¶[0043]). However, modified WITTER does not disclose that a controllable throttle valve is arranged in the medium outlet.
MAKARTCHOUK discloses an exhaust aftertreatment system in which a throttle valve is positioned at the system outlet in FIG. 2, downstream of a diesel particulate filter (DPF 24). Exhaust from the engine (14) flows through a first pipe section into the filter (24), then continues through a second section to the outlet (16), where the throttle valve (30b) is located (¶[0019]).
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Advantageously, MAKARTCHOUK’s throttle valve obstructs the exhaust flow when actuated, thereby regulating the amount of flow through the passageway and enabling control of system pressure and temperature (¶[0005], ¶¶[0023]–[0024]). In view of WITTER’s medium outlet, a person skilled in the art would have been motivated to use MAKARTCHOUK’s throttle valve at the medium outlet to regulate flow and enable control of system pressure and temperature.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate a throttle valve at the outlet, as disclosed by MAKARTCHOUK, into the clean air outlet of the vacuum filtration system by modified WITTER.
Claims 71–72 are rejected under 35 U.S.C. 103 as being unpatentable over WITTER in view of KROEMMER as applied to claim 70 above, and further in view of FRITZE (US20060027267A1).
Regarding Claims 71–72, modified WITTER makes obvious the vacuum filtration system of Claim 70. WITTER discloses that the annular opening (76) consists of multiple discrete penetrations surrounding the central outlet (54) (¶[0050]). However, modified WITTER does not explicitly disclose “each flushing medium inlet is assigned a control valve” (Claim 71), nor “the control valve is electrically operable” (Claim 72).
FRITZE discloses a water delivery system with a filter and an isolation valve that responds to sensed flow conditions, providing control over inlet fluid delivery (¶[0002]). FIG. 1 illustrates appliance 100 with an inlet water line 102, outlet water line 104, appliance water circuit 106, and an actuatable isolation valve 108 (i.e., a control valve). The isolation valve may be electrically, hydraulically, or pneumatically actuated, and is capable of opening and closing via an actuator. In preferred embodiments, the isolation valve is an electrically actuated solenoid valve. The valve may be located internally or in the inlet water line, provided it controls flow into the appliance circuit (¶[0022]).
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Advantageously, FRITZE’s electrically actuated control valve provides automated opening and closing, using a known actuator option to control fluid flow (¶[0022]). In view of modified WITTER’s multiple flushing medium inlets, a person skilled in the art would incorporate FRITZE’s electrically actuated control valve to regulate flow into each inlet, thereby enhancing cleaning precision, supporting programmable timing, and reducing the need for manual actuation, all of which optimize the flushing operation.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate an electrically actuated control valve, as disclosed by FRITZE, to control flow into each flushing medium inlet of the vacuum filtration system by modified WITTER.
Claims 74-75 are rejected under 35 U.S.C. 103 as being unpatentable over WITTER in view of SUTCLIFFE and KROEMMER as applied to claim 55 above, and further in view of FRITZE.
Regarding Claims 74–75, modified WITTER makes obvious the vacuum filtration system of Claim 55. However, modified WITTER does not explicitly disclose “each shutoff valve is a pneumatic valve” (Claim 74), nor “using a flushing medium, the pneumatic valves are operable” (Claim 75).
FRITZE discloses a water delivery system with a filter and an isolation valve that responds to sensed flow conditions, providing control over inlet fluid delivery (¶[0002]). FIG. 1 illustrates appliance 100 with an inlet water line 102, outlet water line 104, appliance water circuit 106, and an actuatable isolation valve 108 (i.e., a control valve). The isolation valve may be electrically, hydraulically, or pneumatically actuated, and is capable of opening and closing via an actuator (¶[0022]).
Advantageously, pneumatic actuation of the isolation valve disclosed by FRITZE provides automated opening and closing of the isolation valve using a known actuator option for controlling fluid flow (¶[0022]). In view of modified WITTER’s inlet and outlet shutoff valves, a person skilled in the art would implement those shutoff valves as pneumatic valves to provide automated valve actuation for control during operation and maintenance.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to implement pneumatic actuation, as disclosed by FRITZE, for the valves used in the vacuum filtration system by modified WITTER.
Claim 82 is rejected under 35 U.S.C. 103 as being unpatentable over WITTER in view of SUTCLIFFE and KROEMMER as applied to claim 76 above, and further in view of SCOTT et al. (US20110265893A1, hereinafter SCOTT).
Regarding Claim 82, modified WITTER makes obvious the vacuum filtration system of Claim 76. However, modified WITTER does not explicitly disclose “a micro filter is connected downstream of the two or more filter devices as viewed in the flow direction of the medium to be filtered.”
SCOTT discloses a filter assembly for an additive manufacturing apparatus, such as a selective laser sintering (SLS) or selective laser melting (SLM) apparatus (¶[0001]). FIG. 1 illustrates a gas flow circuit that includes a primary particulate filter 120 and a downstream HEPA filter 130, both positioned in-line with the gas stream exiting the build chamber (¶[0032]).
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FIG. 1 of SCOTT et al.
A person skilled in the art would provide an additional micro filter downstream of the two filter devices because primary dust separation and cartridge filtration can permit finer particulates to remain entrained in the gas stream. Providing a downstream micro filter is a routine filtration design choice to capture such finer particulates that pass the primary filters, thereby increasing overall filtration efficiency and providing an additional safeguard for downstream flow paths, equipment, or exhaust components (KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416–417, 2007).
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate a downstream micro filter, as disclosed by SCOTT, into the vacuum filtration system by modified WITTER.
Claim 84 is rejected under 35 U.S.C. 103 as being unpatentable over WITTER in view of KROEMMER as applied to claim 83 above, and further in view of VAN HASSEL (US20160207147A1).
Regarding Claim 84, modified WITTER makes obvious the vacuum filtration system of Claim 83. However, modified WITTER does not explicitly disclose “a medium cooler is provided downstream of the fan in the direction of flow.”
VAN HASSEL discloses an additive manufacturing system that processes metallic powders in a controlled chamber atmosphere, where a gas recirculation loop is used to maintain purity and temperature stability of the processing environment (¶[0001]). FIG. 7 illustrates a gas recirculation loop that includes a blower (30) and a heat exchanger (230) in the return leg of the loop (624), positioned in series such that the heat exchanger is downstream of the blower with respect to flow (¶[0057]).
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FIG. 7 of VAN HASSEL
Advantageously, VAN HASSEL’s heat exchanger can be utilized to cool the clean cover gas prior to reintroduction, and the temperature of the clean cover gas can be controlled to facilitate control over the processing temperature (¶[0044]). In view of modified WITTER’s blower vac unit for generating flow through the vacuum filtration system, a person skilled in the art would incorporate VAN HASSEL’s heat exchanger downstream of the blower to cool the medium in the direction of flow.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate a medium cooler downstream of the fan in the direction of flow, as disclosed by VAN HASSEL, into the vacuum filtration system by modified WITTER.
Response to Arguments
Applicant’s arguments, see the Remarks filed November 12, 2025, with respect to the rejection(s) of Claims 55, 57–82 under 35 U.S.C. 103 and Claim 56 under 35 U.S.C. 102(a)(1) have been fully considered. Claim 73 has been canceled. Claims 55, 56, and 74 have been amended. Therefore, the rejection has been withdrawn. However, upon further consideration, new ground(s) of rejection under 35 U.S.C. 103 are made in view of WITTER, SUTCLIFFE, KROEMMER, VOKES, MAKARTCHOUK, FRITZE, SCOTT, and VAN HASSEL. Additionally, Claims 55 and 57 are rejected under 35 U.S.C. 112(b), and Claim 60 is rejected under 35 U.S.C. 112(d).
Conclusion
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/TAK L. CHIU/Examiner, Art Unit 1777
/KRISHNAN S MENON/Primary Examiner, Art Unit 1777