Prosecution Insights
Last updated: April 19, 2026
Application No. 18/077,058

LIQUID FILTER UNIT WITH LATERALLY ARRANGED FILTERS, AND METHOD OF OPERATING THEREOF

Non-Final OA §102§103
Filed
Dec 07, 2022
Examiner
ALI, WAQAAS A
Art Unit
1777
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Entegris Inc.
OA Round
3 (Non-Final)
81%
Grant Probability
Favorable
3-4
OA Rounds
2y 8m
To Grant
99%
With Interview

Examiner Intelligence

Grants 81% — above average
81%
Career Allow Rate
432 granted / 535 resolved
+15.7% vs TC avg
Strong +18% interview lift
Without
With
+18.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
30 currently pending
Career history
565
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
38.2%
-1.8% vs TC avg
§102
29.6%
-10.4% vs TC avg
§112
22.0%
-18.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 535 resolved cases

Office Action

§102 §103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Status Claim(s) 1-10, is/are filed on 01/14/2026 are currently pending. Claim(s) 1-10 is/are rejected. 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 02/18/2026 has been entered. Claim Rejections - 35 USC § 102 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 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 the appropriate paragraphs of pre-AIA 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention. (a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. Claim(s) 1-9 is/are rejected under 35 U.S.C. 102 (a)(1) as being anticipated by Xue (CN 107218102 A). Regarding claim 1, Xue discloses a filter unit for filtering liquid, comprising: a housing (1 and 2) having an inlet (3) and an outlet (4), wherein the inlet and the outlet are disposed on a same side of the housing (top side); a first filter (i.e. 12 – left filter unit) disposed in the housing and including: a first axial end (13) affixed to an inner surface of the housing, an axial inlet (inlet from 3 i.e. 16) disposed over an opening of the inlet of the housing, and a first filter media (11); a second filter (i.e. 6 – middle filter unit 6) disposed in the housing and including: a first axial end (7) affixed to the inner surface of the housing, an axial outlet (10) disposed over an opening of the outlet in the housing, and a second filter media (6), wherein the first filter and the second filter are disposed laterally (fig. 1) with respect to each other within the housing, and wherein the first axial end of the first filter and the first axial end of the second filter are affixed to the same side of the housing (top side); and wherein the first filter and the second filter are configured in a way such that a liquid flow path extending extends from the inlet to the outlet through the first filter media and the second filter media in series such that the liquid is directed from the inlet of the housing through the first filter to the outlet of the housing through the second filter (intended use), wherein the filter unit is configured in a way such that the liquid flow path configured to direct the liquid flows radially outward through the first filter media and to direct the liquid radially inward through the second filter media (intended use) (p. 1-5). Regarding claim 2, Xue teaches wherein the axial inlet (16) of the first filter is formed in the first axial end (13) of the first filter, and the axial outlet (10) of the second filter is formed in the first axial end (7) of the second filter. Regarding claim 3, Xue teaches wherein the first filter media is configured to be a radial outlet of the first filter, and the second filter media is configured to be a radial inlet of the second filter (intended use – however, Xue is teaches this is how it functions). Regarding claim 4, Xue teaches wherein the first filter is spaced apart from the second filter within the housing (fig. 1). Regarding claim 5, Xue teaches wherein the first filter and the second filter are disposed side by side within the housing (fig. 1). Regarding claim 6, Xue teaches wherein the liquid flow path includes, in order: a first portion extending through the first filter along an axis of the first filter, a second portion extending radially outward through the first filter media, a third portion extending from the first filter media to the second filter media, a fourth portion extending radially inward through the second filter media, a fifth portion extending through the second filter along an axis of the second filter (intended use). "[A]pparatus claims cover what a device is, not what a device does." Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original). A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987).“The manner or method in which such machine is to be utilized is not germane to the issue of patentability of the machine itself.” Id.at 580. Regarding claim 7, Xue teaches wherein the third portion extends in a first direction that is radially outward with respect to the first filter and radially inward with respect to the second filter (intended use). Regarding claim 8, Xue teaches wherein the first filter media and the second filter media are depth fibers (i.e. paper) thereof. Regarding claim 9, Xue teaches wherein the first filter media and the second filter media are the same type of filter media (i.e. filter paper). 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 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 pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action: (a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102 of this title, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negatived by the manner in which the invention was made. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under pre-AIA 35 U.S.C. 103(a) are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. 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. Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being obvious by Xue (CN 107218102 A). Regarding claim 10, Xue does not wherein the first filter media and the second filter media are different types of filter media. However, it is well-known to use multiple filters of different types – for example to filter out different type impurities in which the other filter cannot to optimize filtration (see at least US 5342511 A). It would have been obvious to one of ordinary skill to have modified the filters of Koslow for the aforesaid advantages. *** It is noted that any citations to specific, pages, columns, lines, or figures in the prior art references and any interpretation of the reference should not be considered to be limiting in any way. A reference is relevant for all it contains and may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art. See MPEP 2123. Response to Arguments Applicant's arguments with respect to the claims have been considered but are moot because the arguments do not apply to any of the references being used in the current rejection. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Waqaas Ali whose telephone number is (571) 270-0235. The examiner can normally be reached on M-F 9-5 PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Claire Wang can be reached on 571-270-1051. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /WAQAAS ALI/Primary Examiner, Art Unit 1777
Read full office action

Prosecution Timeline

Dec 07, 2022
Application Filed
Jun 13, 2025
Non-Final Rejection — §102, §103
Sep 05, 2025
Response Filed
Nov 15, 2025
Final Rejection — §102, §103
Jan 14, 2026
Response after Non-Final Action
Feb 18, 2026
Request for Continued Examination
Feb 24, 2026
Response after Non-Final Action
Mar 07, 2026
Non-Final Rejection — §102, §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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FLUID FILTER SYSTEM WITH AUTO DRAIN
2y 5m to grant Granted Apr 14, 2026
Patent 12600647
WATER PURIFICATION AND METHOD FOR PURIFYING WATER
2y 5m to grant Granted Apr 14, 2026
Patent 12599855
DOUBLE FILTER APPARATUS INCLUDING GAS SUPPLY TUBE AND SYSTEM INCLUDING THE SAME
2y 5m to grant Granted Apr 14, 2026
Patent 12589338
FILTER AND FILTER DEVICE
2y 5m to grant Granted Mar 31, 2026
Patent 12584193
SEPARATION OF RARE EARTH ELEMENTS
2y 5m to grant Granted Mar 24, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
81%
Grant Probability
99%
With Interview (+18.3%)
2y 8m
Median Time to Grant
High
PTA Risk
Based on 535 resolved cases by this examiner. Grant probability derived from career allow rate.

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