Prosecution Insights
Last updated: April 19, 2026
Application No. 18/321,447

COIL SPRING

Final Rejection §103
Filed
May 22, 2023
Examiner
IRVIN, THOMAS W
Art Unit
3616
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Nhk Spring Co. Ltd.
OA Round
2 (Final)
77%
Grant Probability
Favorable
3-4
OA Rounds
2y 10m
To Grant
91%
With Interview

Examiner Intelligence

Grants 77% — above average
77%
Career Allow Rate
904 granted / 1174 resolved
+25.0% vs TC avg
Moderate +14% lift
Without
With
+14.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
34 currently pending
Career history
1208
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
38.8%
-1.2% vs TC avg
§102
38.1%
-1.9% vs TC avg
§112
19.4%
-20.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1174 resolved cases

Office Action

§103
DETAILED ACTION Response to Arguments Applicant’s arguments with respect to the claims have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. 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. Claims 1-12 and 15-20 are rejected under 35 U.S.C. 103 as being unpatentable over Cliff (US 231,150) in view of Tsuchiya et al. (JP S58-055372). In Re claim 1, Cliff discloses a coil spring (fig. 1) for an automobile, comprising: a rectangular cross-sectional portion (B) with a rectangular cross-sectional portion having upper and lower planes. Hearle fails to teach an elastic coating. Tsuchiya et al. is related to the art of coil springs for automobiles, and teach providing a coil spring (1, 2) with a heat-curable thermosetting plastic elastic coating (3; page 3 describes pre-heating the coil spring between 100°C – 250°C, coating the coil spring with a thermoplastic resin powder, and curing and drying the spring and coating in an oven) to prevent/dampen the sound of the coils colliding with each other (see page 2). Tsuchiya et al. further discuss that the coating may be provided: continuously in the circumferential direction of the spring wire (fig. 3); partially, along individual sections (fig. 2) of the spring wire; on only one side face of the coil spring (fig. 2); or that the coating may be formed thinner than the opposed portions of the spring wire and only at the portions of the spring wire which come into contact with each other (bottom of page 4). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the coil spring of Cliff to include an elastic coating on the coil spring, as taught by Tsuchiya et al., to dampen the sound of the coils colliding with each other during compression. In Re claim 2, see round cross-sectional portion (C) and cross section varying portion (B – C) of Cliff. Tsuchiya et al. further discuss that the coating may be provided continuously (see fig. 3). In Re claims 3, 5, and 9, Tsuchiya et al. further discuss that the coating may be provided continuously (see fig. 3). In Re claim 4, see fig. 2 of Cliff. Tsuchiya et al. further discuss that the coating may be provided continuously (see fig. 3). In Re claim 6, Cliff further shows a cross-section varying portion (B-C and C-B in fig. 1) which have a rectangular shape with arc-shaped corners. Cliff also further shows an end coil with a rectangular cross-sectional shape having arc-shaped corners (bottom of fig. 1). Tsuchiya et al. further disclose that the coating may be only applied to the portions which contact each other (bottom of page 4), thus omitting the edges and sides of the coil spring. In Re claim 7, Tsuchiya et al. further disclose the use of a cured resin thermoplastic, but fail to disclose the specified tear strength characteristics. The examiner points out that these are merely material properties that would be realized and optimized during routine research and development. Therefore, the examiner asserts that it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided the cured resin coating of Tsuchiya et al. to have any tear strength characteristics, including 20-350 kN/m, as a matter of simple engineering design choice, to optimize the strength, elasticity, and noise dampening of the coating. The examiner further notes that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art, and is not patentable (MPEP 2144.05). In Re claim 8, Tsuchiya et al. fail to disclose the specified shear strength characteristics. The examiner points out that these are merely material properties that would be realized and optimized during routine research and development. Therefore, the examiner asserts that it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided the coating of Tsuchiya et al. to have any shear strength characteristics, including 6MPa, as a matter of simple engineering design choice, to optimize the strength, elasticity, and noise dampening of the coating. The examiner further notes that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art, and is not patentable (MPEP 2144.05). In Re claim 10, see fig. 3 and bottom of page 4 of Tsuchiya et al.. In Re claim 11, see figs. 1-3 of Tsuchiya et al.. In Re claim 12, See figs. 1-3 of Tsuchiya et al.. Cliff further shows a cross-section varying portion (B-C and C-B in fig. 1) which have a rectangular shape with arc-shaped corners. Cliff also further shows an end coil with a rectangular cross-sectional shape having arc-shaped corners (bottom of fig. 1). In Re claim 15, see fig. 2 of Tsuchiya et al.. In Re claims 16-19, see figs 1 and 2 of Cliff, which show different round and rectangular cross-sectional portions, and figs. 1-3 of Tsuchiya et al., which show different spatial and coverage arrangements for the coating. In Re claim 20, Cliff shows a rectangular cross-section portion (B). Tsuchiya et al. further disclose that the coating may be only applied to the portions which contact each other (bottom of page 4), thus omitting the edges and sides of the coil spring. Claims 13 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Cliff (US 231,150) in view of Tsuchiya et al. (JP S58-055372) as applied to claim 1 above, and further in view of Hearle (US 338,267). Claims 13 and 14, Cliff further discloses optionally a round and rectangular cross sectional end portions, but fails to teach that the end portions are formed with a tapered end. Hearle is related to art of automotive coil springs, and teaches forming a coil spring (A) with a tapered end portion (a). This tapered end allows the otherwise uneven coil spring to sit flat on a spring seat, which allows for even force distribution and reduces the risk of buckling and tilting of the coil spring under load by increasing the stability. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the coil spring of Cliff to have a tapered end portion, as taught by Hearle, to allow for even force distribution and reduce the risk of buckling and tilting of the coil spring under load by increasing the stability. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. The newly cited reference is relevant to coil springs with varying cross-sectional shape. Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 THOMAS W IRVIN whose telephone number is (571)270-3095. The examiner can normally be reached Monday - Friday 9am - 5pm. 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. /THOMAS W IRVIN/ Primary Examiner, Art Unit 3616
Read full office action

Prosecution Timeline

May 22, 2023
Application Filed
Aug 20, 2025
Non-Final Rejection — §103
Dec 22, 2025
Response Filed
Mar 09, 2026
Final Rejection — §103 (current)

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Prosecution Projections

3-4
Expected OA Rounds
77%
Grant Probability
91%
With Interview (+14.3%)
2y 10m
Median Time to Grant
Moderate
PTA Risk
Based on 1174 resolved cases by this examiner. Grant probability derived from career allow rate.

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