Prosecution Insights
Last updated: April 19, 2026
Application No. 18/563,081

FILTER CARTRIDGE FOR FILTRATION OF LIQUIDS

Non-Final OA §102§103§112
Filed
Nov 21, 2023
Examiner
NORRIS, CLAIRE A
Art Unit
1779
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Brita SE
OA Round
1 (Non-Final)
65%
Grant Probability
Favorable
1-2
OA Rounds
2y 11m
To Grant
94%
With Interview

Examiner Intelligence

Grants 65% — above average
65%
Career Allow Rate
540 granted / 827 resolved
At TC average
Strong +28% interview lift
Without
With
+28.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
48 currently pending
Career history
875
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
42.6%
+2.6% vs TC avg
§102
15.9%
-24.1% vs TC avg
§112
31.9%
-8.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 827 resolved cases

Office Action

§102 §103 §112
DETAILED ACTION Status of Claims: Claims 1-20 are pending. 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 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. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-20 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. Regarding Claim 1: The claim states “the compression device forms a separating device…” This limitation renders the claim indefinite because it is not clear if the term “forms” is intended as a process limitation such that the function of the compression device is to form a separating device, if the limitation requires the compression device to comprise a separating device, the limitation requires the compression deice to separate the two filter media, or something else. For the purposes of examination “forms a separating device” will be interpreted as the compression device separates the two filter media. The claim states “the compression device is designed in such a way that the compression device can carry out an expansion movement…” The phrase “designed in such a way” renders the claim indefinite because it is not clear if this is intended to be a means plus function limitation, if a specific structure is being required, or if this is purely a functional limitation. For the purposes of examination “can carry out an expansion movement” will be interpreted as a functional limitation. Regarding Claim 2: The claim refers to “a pressure element”, however claim 1 requires “two pressure elements”. It is therefore not clear if an additional pressure element is being required or if one of the two pressure elements of claim 1 is being further limited. The claim states “like a piston”. It is not clear what type of movement is considered to be “like a piston”. The movement is not described in the specification, therefore any movement forcing the pressure element into the filter section is considered to be “like a piston” Regarding Claim 7: The claim refers to “a filter chamber section”, however claim 1 requires “two filter chamber section”. It is not clear if an additional filter chamber section is being required or not. The claim refers to “the pressure element”, however claim 1 requires “two pressure elements”. It is not clear if only one of the pressure elements is required to be pressed by the spring. Regarding Claim 9 and 18: The claim states “two separating elements formed by respective ones of the pressure elements”. It is not clear if the separating elements are the pressure elements such that the function of the pressure elements includes separating or if the separating elements is a distinct part of the pressure element. Regarding Claims 12 and 19: The claims refer to “the separating element” however claims 9 and 18, from which they depend, require two separating elements. It is therefore not clear if only one is being limited and if so, which one of the two separating elements. The claim states “the filter cartridge has at least one of the following features… a)an intermediate layer…b)wherein the intermediate layer…” All the features b)-d) refer to “the intermediate layer” however it is not clear if “the intermediate layer” is that limited by feature a) or any “intermediate layer” since “a)” is not required by the claims. Regarding Claim 13: The claim uses the term “preferably”. This term renders the claim indefinite because it is not clear if the limitations that follow are required by the claim or not. Regarding Claims 14 and 20: The claims use the term “loosely”. This term renders the claim indefinite because it is not clear what type of arrangement would be considered “loosely” arranged. Regarding Claims 15 and 20: The claim requires “one or more bass ducts”. It is not clear if the bypass ducts are separate from the “fluid conductive connection” required by claim 1 or further limiting the fluid conductive connection. The remaining claims are indefinite as they depend from an indefinite claim. 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 (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 the appropriate paragraphs of 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. Claim(s) 1-10, 12, and 14-17 is/are rejected under 35 U.S.C. 102(a)1) as being anticipated by Wada (JP 2000279951, Cited in IDS, English machine translation provided for citations). Regarding Claim 1: Wada teaches the filter cartridge for the filtration of liquids, wherein the filter cartridge has a filter chamber housing (cylindrical container 1) with an inlet opening (water introduction part 4) and with an outlet opening (water discharge part 3) for a liquid flowing through the filter chamber housing, wherein at least one filter medium (filtering layers) for the filtration of the liquid flowing through is arranged within a filter chamber volume enclosed by the filter chamber housing, and wherein the filter cartridge has a compression device with at least one compression element (spring body 5), with which a compression force can be exerted on the filter medium in order to compress the filter medium (filter layers pressed by the spring body) (see Abstract, fig. 1), wherein the filter cartridge has two filter chamber sections (upper and lower filter layers) (see Abstract) which are each filled with a granular filter medium (sand granular magnetite filtration layer 2C) (see pg. 2, last paragraph, pg. 4, 10th paragraph, fig. 1) and between which the compression device is arranged (see fig. 1), wherein the compression device forms a separating device with which the two filter media in the two filter chamber sections are separated from one another (upper and lower layers are separated) (see fig. 1), the separating device allowing for or being bypassed by a fluid-conductive connection between the filter chamber sections (creates the separated water passage 6) (see pg. 2, 11th paragraph, fig. 1) wherein the compression device is designed in such a way that the compression device can carry out an expansion movement and a compressive force is thereby exerted on the filter medium in each of the two filter chamber sections (both the upper and lower filter layers are directly pressed) (see pg. 2, 5th paragraph), and wherein the at least one compression element (spring 5) is arranged between two pressure elements (perforated plates 7), each of which is pressed into a respective filter chamber section by the expansion movement (see pg. 3, 1st paragraph, fig. 1). Regarding Claim 2: Wada teaches the filter cartridge according to claim 1 having a pressure element with any one of features (i) to (iv): (i) the pressure element can be moved like a piston into the interior of the respective filter chamber section (the pressure element is pressed into the respective filter chamber, therefore it is “like a piston”) (see pg. 3, 7th paragraph, fig. 1); or (ii) a surface of the pressure element is smaller than a cross-sectional area of the interior of the filter chamber section and a deformable membrane is mounted in a liquid-tight manner between an outer edge of the pressure element and an inner wall of the filter chamber housing that surrounds the pressure element; or (iii) a membrane fully covering a cross-sectional area of the interior of the filter chamber housing is provided in the filter chamber section, against which membrane the pressure element is pressed and through which the pressure element applies pressure; or (iv) an intermediate layer is arranged between the pressure element and the filter medium to retain particles of the granular filter medium. Regarding Claim 3: Wada teaches the filter cartridge according to claim 1, wherein the compression device is arranged to carry out a contraction movement in case a volume of the filter medium increases during a service life of the filter cartridge. The compression device is a spring (see Abstract), springs can contract or expand. Regarding Claim 4: Wada teaches the filter cartridge according to claim 1, wherein the compression device is completely enclosed by the filter chamber housing (see fig. 1). Regarding Claim 5: Wada teaches the filter cartridge according to claim 1, wherein the compression device is at least partially made of an elastically deformable material (a spring) (see Abstract). Regarding Claim 6: Wada teaches the filter cartridge according to claim 1, wherein the pressure element is made of an inelastic material (perforated plate, is not disclosed as being elastic and partitions the material therefore it is inherently inelastic as it stays retaining the filter media when pressed by the spring) (see pg. 3, 1st paragraph). Regarding Claim 7: Wada teaches the filter cartridge according to claim 1, wherein the at least one compression element comprises a spring device (spring body 5) (see Abstract, fig. 1), and wherein the pressure element (perforated plate 7) is pressed into a filter chamber section by means of the spring device to generate the compressive force acting on the filter medium (see pg. 3, 1st paragraph, fig. 1). Regarding Claim 8: Wada teaches the filter cartridge according to claim 7, wherein the spring device comprises one or more spring elements (a spring body 5) (see Abstract, fig. 1). Regarding Claim 9: Wada teaches the filter cartridge according to claim 7, wherein the separating device comprises two separating elements (perforated plates 7) formed by respective ones of the pressure elements, between which the spring device (spring body 5) is arranged in such a way that the two separating elements are each pressed outward with respect to each other (see fig. 1). Regarding Claim 10: Wada teaches the filter cartridge according to claim 9, wherein the separating element comprises one or more flow-through openings through which liquid can pass (plate is perforated therefore it has flow through openings) (see pg. 3, 1st paragraph). Regarding Clam 12: Wada teaches the filter cartridge according to claim 9, wherein the filter cartridge has at least one of the following features a) to d): a) an intermediate layer (active carbon filtration layer 2A) is arranged between the separating element (perforated plate 7) and the filter medium (filtration layer 2C) (see pg. 4 paragraphs 6-10, fig. 1), b) wherein the intermediate layer comprises a filter material, c) the intermediate layer is made of an expansion medium whose volume increases in case of contact with liquid, d) the intermediate layer is made of an elastic material that can be compressed in case of an expansion of the filter medium. Regarding Claim 14: Wada teaches the filter cartridge according to claim 1, wherein the compression device is loosely arranged between the two filter chamber sections inside of the filter chamber housing. Any arrangement is considered to be “loosely arranged” Regarding Claim 15: Wada teaches the filter cartridge according to claim 1, provided with one or more bypass ducts separate from the compression device or with openings (perforations in perforated plate) within the compression device that allow for a free flow of fluid through the compression device (see fig. 1, pg. 2, 11th paragraph, pg. 3, 1st paragraph). Regarding Claim 16: Wada teaches the filter cartridge according to claim 2, wherein the compression device is arranged to carry out a contraction movement in case a volume of the filter medium increases during a service life of the filter cartridge, wherein the compression device is completely enclosed by the filter chamber housing, and wherein the compression device is at least partially made of an elastically deformable material ( a spring) (see Abstract, fig. 1). Regarding Claim 17: Wada teaches the filter cartridge according to claim 16, wherein the pressure element is made of an inelastic material (perforated plate, is not disclosed as being elastic and partitions the material therefore it is inherently inelastic as it stays retaining the filter media when pressed by the spring) (see pg. 3, 1st paragraph), wherein the at least one compression element comprises a spring device (spring body) (see Abstract), wherein the pressure element is pressed into a filter chamber section by means of the spring device to generate the compressive force acting on the filter medium, and wherein the spring device comprises one or more spring elements (see Abstract, fig. 1). 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 factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 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) 11 and 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wada (JP 2000279951, Cited in IDS, English machine translation provided for citations). Regarding Claim 11: Wada teaches the filter cartridge of claim 1. Wada is silent to the material of the compression device or the compression device being one piece. However it would have been obvious to use an integrated construction and make the compression device one piece. The use of a one-piece, integrated construction instead of the structure disclosed or taught in the prior art would have been within the ambit of a person of ordinary skill in the art. See In re Larson, 340 F.2d 965, 968, 144 USPQ 347, 349 (CCPA 1965) (see MPEP § 2144.04). Regarding Claim 18: Wada teaches the filter cartridge according to claim 17, wherein the separating device comprises two separating elements (perforated plates 7) formed by respective ones of the pressure elements, between which the spring device (spring body 5) is arranged in such a way that the two separating elements are each pressed outward with respect to each other, wherein the separating element comprises one or more flow-through openings (perforations) through which liquid can pass (see fig. 1, pg. 2, 11th paragraph, pg. 3, 1st paragraph). Wada is silent to the material of the compression device or the compression device being one piece. However it would have been obvious to use an integrated construction and make the compression device one piece. The use of a one-piece, integrated construction instead of the structure disclosed or taught in the prior art would have been within the ambit of a person of ordinary skill in the art. See In re Larson, 340 F.2d 965, 968, 144 USPQ 347, 349 (CCPA 1965) (see MPEP § 2144.04). Regarding Claim 19: Wada teaches the filter cartridge according to claim 18, wherein the filter cartridge has at least one of the following features a) to d): a) an intermediate layer (active carbon filtration layer 2A) is arranged between the separating element (perforated plate 7) and the filter medium (filtration layer 2C) (see pg. 4 paragraphs 6-10, fig. 1), b) wherein the intermediate layer comprises a filter material, c) the intermediate layer is made of an expansion medium whose volume increases in case of contact with liquid, d) the intermediate layer is made of an elastic material that can be compressed in case of an expansion of the filter medium, and wherein the compression element is balloon-shaped; preferably the balloon-shaped compression element is a balloon made of an elastic and pressure-tight material filled with compressed air Regarding Claim 20: Wada teaches the filter cartridge according to claim 19, wherein the compression device is loosely arranged between the two filter chamber sections inside of the filter chamber housing, and wherein the filter cartridge is provided with one or more bypass ducts separate from the compression device or with openings (perforations in perforated plate) within the compression device that allow for a free flow of fluid through the compression device (see fig. 1, pg. 2, 11th paragraph, pg. 3, 1st paragraph). Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wada (JP 2000279951, Cited in IDS, English machine translation provided for citations) as applied to claim 1 above, and further in view of Duan (CN 102910752, Cited in IDS, English machine translation provided for citations). Regarding Claim 13: Wada teaches the filter cartridge according to claim 1. Wada does not teach the compression element is balloon-shaped; preferably the balloon-shaped compression element is a balloon made of an elastic and pressure-tight material filled with compressed air. Duan teaches a balloon-shaped compression element (air bag 63) (see para. 0023, 0049) within a filter cartridge (see fig. 2). Wada and Duan are analogous inventions in the art of water filters. It would have been obvious to one skilled in the art before the effective filing date of the invention to replace the spring of Wada with the balloon-shaped element of Duan, because it is the simple substitution of one known compression element with another known compression element able to exert pressure on a filtration medium, obviously resulting pressure being applied to both filter media with an expectation of success. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. __,__, 82 USPQ2d 1385, 1395 – 97 (2007) (see MPEP § 2143, B.). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CLAIRE A NORRIS whose telephone number is (571)272-5133. The examiner can normally be reached M-Th 7:30-5 F: 8-12. 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, Ramdhanie Bobby can be reached at 571-270-3240. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /CLAIRE A NORRIS/Primary Examiner, Art Unit 1779 2/9/2026
Read full office action

Prosecution Timeline

Nov 21, 2023
Application Filed
Feb 09, 2026
Non-Final Rejection — §102, §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
65%
Grant Probability
94%
With Interview (+28.2%)
2y 11m
Median Time to Grant
Low
PTA Risk
Based on 827 resolved cases by this examiner. Grant probability derived from career allow rate.

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