Prosecution Insights
Last updated: April 19, 2026
Application No. 18/380,606

DOUBLE CHAMFERED HYDRAULIC COMPRESSION STOP SLEEVE

Non-Final OA §103
Filed
Oct 16, 2023
Examiner
SAHNI, VISHAL R
Art Unit
3616
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Beijingwest Industries Co. Ltd.
OA Round
1 (Non-Final)
75%
Grant Probability
Favorable
1-2
OA Rounds
2y 7m
To Grant
95%
With Interview

Examiner Intelligence

Grants 75% — above average
75%
Career Allow Rate
731 granted / 970 resolved
+23.4% vs TC avg
Strong +19% interview lift
Without
With
+19.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
46 currently pending
Career history
1016
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
39.5%
-0.5% vs TC avg
§102
33.1%
-6.9% vs TC avg
§112
24.3%
-15.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 970 resolved cases

Office Action

§103
DETAILED ACTION This is a first Non-Final Office Action on the merits in response to the application filed 10/16/23. The request for foreign priority to a corresponding CN application filed 02/22/23 has been received and is proper. Claims 1-20 are currently pending yet all are rejected as detailed below. 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 § 103 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. Kus in view of Slusarczyk Claim(s) 1-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kus (EP 3358213) in view of Slusarczyk et al. (U.S. Patent No. 9,657,803). Kus is directed to a hydraulic damper with a hydraulic compression stop arrangement. See Abstract. Slusarczyk is also directed to a hydraulic damper with a hydraulic stop arrangement. See Abstract. Note: Slusarczyk is a corresponding U.S. Patent of a “Y” reference in the cited EPO Written Opinion. Claim 1: Kus discloses a hydraulic compression stop (HCS) sleeve (81) [Fig. 7] for a damper assembly [Figs. 2-3b], comprising: an HCS body (81) having a tubular shape (8132) and defining a chamfer opening (8131) for receiving an HCS piston (83). See Figs. 2-3b, 7. Kus discloses all the limitations of this claim except for “the HCS body defining a plurality of ribs extending inwardly from the chamfer opening.” While Kus discloses the use of ribs (811), they extend radially outwards (rather than inwards) from the sleeve/chamfer opening. See Fig. 6. Slusarczyk discloses a hydraulic damper (1a) with an HCS stop formed in the lower section of an HCS body (8) with a chamfer opening (32) for receiving an HCS piston (13), wherein the HCS body defines a plurality of ribs (15) extending radially inwardly from the chamfer opening [see Figs. 5a-7] and configured to progressively guide the HCS piston apart from the chamfer opening as the HCS piston enters the HCS body/sleeve [see Figs. 3a, 3b]. See Figs. 1, 5a-7. It would have been obvious to a person having ordinary skill in the art at the effective filing date of the invention to include this feature because, aside from Kus already employing the use of a plurality of ribs extending from the HCS body, adding the tapered ribs that extend inwardly from the sleeve can account for abrupt increases in pressure due to piston compression, which can cause leakage and/or compromise piston sealing rings and overall functionality. Including the Slusarczyk ribs would provide a smoother, more gradual, increase in damping force and extend the longevity of the device. Claim 2: Slusarczyk discloses that the plurality of ribs are spaced apart from one another at regular angular intervals. See Figs. 5a-7. Claim 3: Kus discloses that the HCS body includes an interior surface defining a plurality of grooves (814) extending axially therein. See Fig. 7. Slusarczyk discloses that each rib of the plurality of ribs is circumferentially spaced. See Figs. 5a-7. It would be obvious for the ribs to be between two adjacent grooves since this provides adequate spacing for these components which are both circumferentially spaced around the inside of the sleeve. Claim 4: Slusarczyk discloses that at least one rib of the plurality of ribs defines a sloped surface facing out of the HCS body and toward the HCS piston with the HCS piston outside of the HCS sleeve. See Figs. 5a-7. Claim 5: Slusarczyk discloses that the tubular shape of the HCS body includes an annular rim, and wherein the sloped surface of the at least one rib is adjacent to the annular rim of the HCS body. See Figs. 5a-7. Claim 6: Slusarczyk discloses that the tubular shape of the HCS body includes an annular rim, and the chamfer opening defines a taper angle between the annular rim and a cylindrical inner surface of the HCS body, and wherein the sloped surface of the at least one rib defines an angle that is shallower than the taper angle of the chamfer opening. See Figs. 5a-7. Claim 7: Slusarczyk discloses that the taper angle of the chamfer opening defines a constant slope between the annular rim and the cylindrical inner surface of the HCS body. See Figs. 5a-7. Claim 8: Slusarczyk discloses that the at least one rib includes a lower surface adjacent to the sloped surface and extending generally parallel to a cylindrical inner surface of the HCS body. See Figs. 5a-7. Claim 9: Slusarczyk discloses that the at least one rib includes a knee having a gradual curvature between the sloped surface and the lower surface. See Figs. 5a-7. Claim 10: Slusarczyk discloses that the plurality of ribs includes six of the ribs. See Figs. 5a-7. Claim 11: Kus and Slusarczyk is relied upon as in claim 1 above. Kus further discloses that the HCS piston includes a piston extension (51) with a piston ring (83) disposed thereupon. See Fig. 2. Claims 12-20: see claims 2-10 above, respectively. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to VISHAL R SAHNI whose telephone number is (571)270-3838. The examiner can normally be reached M-F 7am-3pm PST. 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, Robert Siconolfi can be reached at 571-272-7124. 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. VISHAL SAHNI Primary Examiner Art Unit 3657 /VISHAL R SAHNI/Primary Examiner, Art Unit 3616 December 31, 2025
Read full office action

Prosecution Timeline

Oct 16, 2023
Application Filed
Dec 31, 2025
Non-Final Rejection — §103 (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
75%
Grant Probability
95%
With Interview (+19.3%)
2y 7m
Median Time to Grant
Low
PTA Risk
Based on 970 resolved cases by this examiner. Grant probability derived from career allow rate.

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