Prosecution Insights
Last updated: April 19, 2026
Application No. 18/044,346

LEAF SPRING WITH HIGH RESOLUTION STIFFNESS CONTROL

Non-Final OA §102§112
Filed
Mar 07, 2023
Examiner
SNOW, BRUCE EDWARD
Art Unit
3774
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Massachusetts Institute Of Technology
OA Round
1 (Non-Final)
75%
Grant Probability
Favorable
1-2
OA Rounds
3y 0m
To Grant
84%
With Interview

Examiner Intelligence

Grants 75% — above average
75%
Career Allow Rate
745 granted / 995 resolved
+4.9% vs TC avg
Moderate +9% lift
Without
With
+8.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
37 currently pending
Career history
1032
Total Applications
across all art units

Statute-Specific Performance

§101
2.2%
-37.8% vs TC avg
§103
30.1%
-9.9% vs TC avg
§102
27.9%
-12.1% vs TC avg
§112
26.4%
-13.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 995 resolved cases

Office Action

§102 §112
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 . Election/Restrictions Applicant’s election of Group 1 in the reply filed on 1/22/2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)). Claims 5-12 and 15 are withdrawn from prosecution. Specification The disclosure is objected to because of the following informalities: Claim 4, the slots are a critical element of the elected species and fail to include a reference numeral. Claim 1, the “controller” fails to include a reference numeral. Claim 1, “a mechanical ground” fails to include a reference numeral Appropriate correction is required. Drawings The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they include the following reference character(s) not mentioned in the description: Please add the reference numeral for the slots, the controller and mechanical ground to the drawings for each embodiment. Corrected drawing sheets in compliance with 37 CFR 1.121(d), or amendment to the specification to add the reference character(s) in the description in compliance with 37 CFR 1.121(b) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance. 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 1-4, 13-14 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 1 claims multiple actuators, each actuator associated with an individual leaf spring. Claim 3 claims the actuator locks the end of the individual springs to the mechanical ground by extending a pin through the spring. Is the pin the actuator? The term “actuator” is believed to not exist on the embodiment using pins. Claim 1 is ambiguous. Claim 1, the elected embodiment uses a pin. The controller is ambiguous as to what is being claimed. 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. Claims 1-2, 13-14, 16-18 and 20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Herr et al Herr (2004/00664195). Herr teaches a variable stiffness spring assembly comprising: PNG media_image1.png 624 482 media_image1.png Greyscale multiple leaf springs (600 with 608) joined to bend together and to slide relative to each other, with ends of the leaf springs displaced axially (longitudinally) relative to each other with bending (compare figures 12a and 12b; see par. 0072); a mechanical ground (at least 602, the springs 600 with the permanently bonded plate 605 may be consider a portion of the mechanical ground); multiple actuators 608, each actuator associated with an individual leaf spring of the multiple leaf springs, each actuator limiting axial displacement of an end of the individual leaf spring relative to the mechanical ground independent of other leaf springs; and a controller (the user or microprocessor par. 0029) configured to control each actuator. Claim 2, the (binding) actuator 608 actuator limits axial displacement of the individual end of the spring by locking the end of the individual spring to the mechanical ground. Claim 13, the spring connected to 603 with the permanently bonded plate 605 is the mechanical ground. Claim 14, as shown above, the assembly is configured as a lower extremity prosthesis. Further, see at least claims 1-11. Claim 16: see the interpretation of the variable stiffness spring assembly in claim 1 above. The axial displacement (interpreted as longitudinal displacement) of an end of each leaf spring (600 with 608) relative to the mechanical ground (at least 602 may include the springs 600 with the permanently bonded plate 605) is limited relative to other leaf springs (600 with 608) via the actuator and controller. Claim 17, axial displacement is limited by multiple actuators 608, each actuator associated with an individual leaf spring of the multiple leaf springs, and a controller (the user or microprocessor par. 0029) configured to control each actuator. Claim 18, actuator 608 limits axial displacement of the individual end of the spring by locking the end of the individual spring to the mechanical ground (at least 602, the springs 600 with the permanently bonded plate 605 may be consider a portion of the mechanical ground). Claim 20, a method as claimed in claim 16 applied to a lower extremity prosthesis. See at least claims 1-11. Allowable Subject Matter Claims 3-4 and 19 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The following is an examiner’s statement of reasons for allowance: Herr is considered the closes prior art of record, however, fails to teach the combination of claims 1 or 16 further comprising wherein each actuator locks the end of the individual spring to the mechanical ground by extending a pin through the individual spring and the mechanical ground. Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.” Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRUCE EDWARD SNOW whose telephone number is (571)272-4759. The examiner can normally be reached 7:30 am - 5:00 pm Monday through Thursday. 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, Melanie Tyson can be reached at 5712729062. 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. /BRUCE E SNOW/Primary Examiner, Art Unit 3774
Read full office action

Prosecution Timeline

Mar 07, 2023
Application Filed
Feb 12, 2026
Non-Final Rejection — §102, §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
75%
Grant Probability
84%
With Interview (+8.8%)
3y 0m
Median Time to Grant
Low
PTA Risk
Based on 995 resolved cases by this examiner. Grant probability derived from career allow rate.

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