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 .
Claim Objections
Claim 57 objected to because of the following informalities:
The phrase “a reduction of the negative pressure equalization in the filter housing” should be corrected to read “a reduction of the negative pressure to equalize pressure in the filter housing” for correct wording.
Claim 60 objected to because of the following informalities:
The phrase “filtered material collection chamber” should be corrected to read “filtered material collecting chamber” for consistency.
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 55-57, 59-64, 66-72, and 74-84 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 “the filtered material collecting chamber” in the 4th paragraph of the claim. This limitation lacks clear antecedent basis in the claim. Claims 57, 59, 61-64, 67-69, and 74-82, which depend from Claim 55, are similarly rejected by virtue of dependency.
Claim 56 recites the limitation “the transfer line” in the 5th paragraph of the claim. This limitation lacks clear antecedent basis in the claim. It is unclear whether “the transfer line” refers to the previously recited “transition line.” Claims 60, 66, 70-72, and 83-84, which depend from Claim 56, are similarly rejected by virtue of dependency.
Claim 57 recites the limitation “a reduction of the negative pressure equalization in the filter housing.” This limitation is unclear because it is unclear whether the limitation refers to a reduction of negative pressure or pressure equalization in the filter housing.
Claim 66 recites the limitation “the filter wall” in the claim. This limitation lacks clear antecedent basis in the claim.
Allowable Subject Matter
Claims 55-57, 59-64, 66-72, and 74-84 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) set forth in this Office action.
The following is a statement of reasons for the indication of allowable subject matter:
The amended Claim 55 clarifies the structural relationship and function of the discharge valve within the negative-pressure cleaning arrangement, including evacuation of the filter housing by a vacuum pump, maintaining negative pressure in the filtered material collecting chamber during flushing, and opening the discharge valve after pressure equalization to feed filtered material into the collecting chamber by the maintained negative pressure, thereby overcoming the previous prior art rejection.
The amended Claim 56 clarifies the structural relationship and function of the filtered material collecting chamber shutoff valve, including the valve cone being held open by a holder when the collecting chamber is attached to the filter housing and automatically closing in a spring-supported manner when the collecting chamber is removed to hermetically enclose an inert gas atmosphere, thereby overcoming the previous prior art rejection.
The most relevant prior art of record includes WITTER et al. (US20140223690A1), SUTCLIFFE et al. (US20180244034A1), KROEMMER et al. (US20030075085A1), VOKES (US2544244), MAKARTCHOUK et al. (US20110252765A1), FRITZE (US20060027267A1), SCOTT et al. (US20110265893A1), and VAN HASSEL (US20160207147A1). These references collectively represent the closest technical disclosures pertinent to the claimed invention. For further details regarding these disclosures, reference is made to the 35 U.S.C. § 103 rejection in the Non-Final Office Action filed February 09, 2026.
A further search of the prior art has been conducted, including consideration of KLEEMANN et al. (DE102018002314A1) and BRADEN (US6394708B1). KLEEMANN was considered as a closest additional primary reference, and BRADEN was considered for its pressure-based discharge concept.
KLEEMANN discloses a filter device for particle-laden welding gases generated during 3D-printer manufacturing in a production room (¶[0001]).
FIG. 2 illustrates pre-filter device 54 having first and second pre-filters 55 and 56 (i.e., a filter housing with a filter). Particle-laden raw gas from raw gas line 57 is supplied to unfiltered sides 61 of pre-filters 55 and 56 (i.e., a medium inlet) through blocking devices 6 and 9 (i.e., shutoff valves). The raw gas flows tangentially along the housings of pre-filters 55 and 56 to create a cyclone effect, causing particles adhering to the filter material to detach and fall into receiving containers 59 attached under the pre-filters (i.e., a filtered material collecting chamber). The filtrate sides 63 of pre-filters 55 and 56 are connected to clean gas line 22 (i.e., a medium outlet) through shut-off devices 5 and 8 (i.e., shutoff valves). The filtrate side 67 of main filter 24 is connected to suction side 71 of compressor 73 through shut-off device 14 and supply line 69 (¶[0019]).
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In an operating state, pre-filter 56 is in filtration operation with shut-off devices 9 and 8 open, while shut-off devices 6 and 5 on first pre-filter 55 are closed (i.e., the shutoff valves are in the closed position) (¶[0021]).
Pre-filters 55 and 56 operate in an alternating configuration. When second pre-filter 56 remains in filtration operation, pressure from the preceding backflushing process in first pre-filter 55 pushes particle-containing oil from receiving container 59 back to oil filters NF1 and NF2 through shut-off device 3 and shut-off device 2, emptying receiving container 59 (¶[0026]). Conversely, when first pre-filter 55 remains in filtration operation, pressure built up during backflushing in second pre-filter 56 pushes particle-containing oil from receiving container 59 back to oil filters NF1 and NF2 through shut-off device 4 and shut-off device 2, emptying receiving container 59 (¶[0028]).
To prepare both pre-filters 55 and 56 for inerting, negative pressure is created in the housings of pre-filters 55 and 56 by connecting pressure side 75 of compressor 73 to pressure accumulator 79 through open shut-off device 16, connecting suction side 71 of compressor 73 to filtrate sides 63 of pre-filters 55 and 56 through open shut-off devices 7 and 10, and running compressor 73. After vacuum is created in the housings of pre-filters 55 and 56, shut-off devices 2, 3, and 4 remain open, and shut-off devices 16 and 18 are opened, such that the vacuum draws oil from oil filters NF1 and NF2 into pre-filters 55 and 56, filling receiving containers 59 and the filter housings with the filter material with inerting white oil (¶[0029]-[0030]). Accordingly, the compressor functions as a vacuum pump for the pre-filters, and the vacuum is applied during inerting to draw white oil into the receiving containers and the filter housings with the filter material.
KLEEMANN is close to the amended filter-device environment, but KLEEMANN uses receiving containers, white oil/inerting, and NF1/NF2 oil filters as its particle-handling path rather than a separate filter-to-collecting-chamber discharge-valve arrangement for preserving chamber pressure during flushing. BRADEN was therefore considered for its pressure-based discharge concept.
BRADEN discloses a pneumatic conveyor receiver for separating conveyed solids from air (Col. 1, Lns. 5-8). Specifically, the receiver includes an upstanding receptacle with an inlet port and a gravity feed discharge opening. A flow control valve at the discharge opening controls discharge flow of particulate matter, and the flow control valve includes a valve seat circumscribing the discharge opening and a tapered plug selectively engageable with the valve seat to occlude the discharge opening (Col. 1, Lns. 36-45).
FIG. 2 illustrates solids/air separating receiver 18 having upstanding hollow receptacle 38 with interior space 40, cylindrical midsection 44, and frusto-conical gravity fed hopper 46. Hollow air outlet fitting 54 communicates with interior space 40 and includes side fitting 58 connected to vacuum piping 22, while tangential inlet port 26 communicates with interior space 40 through cylindrical midsection 44 (Col. 3, Lns. 15-42).
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At the lower terminus of hopper 46, valve plate 70 defines discharge opening 72, and discharge opening 72 is circumscribed by annular valve seat 74 (Col. 3, Lns. 43-59). Tapered plug 76 is disposed coaxially with discharge opening 72 and annular valve seat 74, and plug 76 engages valve seat 74 from below without passing entirely through discharge opening 72 into space 40 (Col. 3, Ln. 60-Col. 4, Ln. 11). Plug 76 and valve seat 74 cooperate to form flow control valve 78 at discharge opening 72, which controls discharge flow of particulate matter and selectively creates a substantially air tight seal to prevent ambient air from entering receptacle 38, allowing vacuum to be drawn in receptacle 38 when flow control valve 78 is closed (Col. 4, Lns. 12-21).
To provide selective opening and closing of flow control valve 78, valve plug 76 extends into and is mounted to receptacle 38 to permit reciprocal motion of plug 76 along the vertical axis of receptacle 38 and substantially parallel to the discharge flow of particulate matter through discharge opening 72. The reciprocal motion of plug 76 is achieved by stem 80 connected to plug 76 and actuator 82 connected to stem 80 (Col. 4, Lns. 32-48).
During operation, actuator 82 lifts stem 80 and plug 76 into engagement with valve seat 74, and vacuum drawing apparatus 20 draws vacuum in receptacle 38. As pressure within receptacle 38 decreases, ambient air pressure pushes plug 76 into tight engagement with annular valve seat 74, effecting an air tight seal of discharge opening 72. After collected particulate matter gathers in hopper 46, pressure is equalized by opening a relief air valve, and plug 76 is displaced downwardly away from valve seat 74 to open flow control valve 78 and permit collected particulate matter to exit through discharge opening 72 (Col. 4, Ln. 56-Col. 5, Ln. 29).
After considering BRADEN, there is no sufficient reason to incorporate BRADEN’s pressure-based discharge concept into KLEEMANN. KLEEMANN already provides a working particle-handling path using receiving containers, white oil/inerting, and NF1/NF2 oil filters, and does not need BRADEN’s pressure-based discharge concept to perform its particle-handling operation or pressure operation. WITTER was also considered because it uses a pulse-cleaning system, but WITTER’s pulse-cleaning system does not provide a reason to modify KLEEMANN’s white-oil/inerting particle-handling path to include the amended pressure-based discharge and collecting-chamber features. The remaining prior art previously relied upon in the rejection was also considered, but those references do not provide a sufficient reason to modify KLEEMANN to arrive at the amended claim features without relying on hindsight.
Response to Arguments
Applicant’s arguments, see Applicant’s Remarks and amended claims filed April 30, 2026, with respect to the rejection of claims 55-57, 59-64, 66-72, and 74-84 under 35 U.S.C. 103, have been fully considered and are persuasive. The previous rejection has been withdrawn.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAK L. CHIU whose telephone number is (703)756-1059. The examiner can normally be reached M-F: 9:00am - 6:00pm (CST).
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/TAK L. CHIU/Examiner, Art Unit 1777
/PREM C SINGH/Supervisory Patent Examiner, Art Unit 1771
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