Prosecution Insights
Last updated: April 19, 2026
Application No. 18/451,333

MULTI-START LEADSCREW FOR VARIABLE FILLING AND PERFORMANCE

Non-Final OA §103
Filed
Aug 17, 2023
Examiner
STIMPERT, PHILIP EARL
Art Unit
3783
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Insulet Corporation
OA Round
1 (Non-Final)
63%
Grant Probability
Moderate
1-2
OA Rounds
3y 9m
To Grant
99%
With Interview

Examiner Intelligence

Grants 63% of resolved cases
63%
Career Allow Rate
537 granted / 857 resolved
-7.3% vs TC avg
Strong +49% interview lift
Without
With
+49.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
85 currently pending
Career history
942
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
50.1%
+10.1% vs TC avg
§102
20.5%
-19.5% vs TC avg
§112
26.7%
-13.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 857 resolved cases

Office Action

§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 . 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. Claim(s) 1-2, 5-6, and 9-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over US Pre-Grant Publication 2003/0199824 to Mahoney et al. (Mahoney hereinafter) in view of US Pre-Grant Publication 2003/0115981 to Stoianovici et al. (Stoianovici) Regarding claim 1, Mahoney teaches a device (10) for delivering fluid do a user, comprising a reservoir (30), a plunger (204), a threaded lead screw (202), an actuator (214, 220), and a processor (50, see e.g. paragraph 59). Mahoney does not teach that the lead screw is a multi-start lead screw. Stoianovici teaches a ball-worm transmission generally, and particularly teaches a driven gear (200) and a multi-start lead screw (100). Stoianovici teaches that the lead screw may be made multi-start for when high power/low transmission ratios are desired (paragraph 60). One of ordinary skill in the art would have found it obvious before the effective filing date of the application to use a multi-start lead screw as taught by Stoianovici in the device of Mahoney in order to improve its high power and/or low transmission ratio aspects. Regarding claim 2, Mahoney teaches a worm drive (i.e. the threads of the lead screw) and a ratchet gear (214, see e.g. Fig. 4 and paragraph 75). Regarding claim 5, Mahoney teaches a restrictor (216) which prevents linear movement of the lead screw (e.g. along the axis of the shape memory actuator 220) but permits rotational movement. Regarding claim 6, inasmuch as the restrictor contacts and supports the actuator (at 214) and the lead screw (202, at least indirectly), it serves as a bearing surface. Regarding claim 9, Mahoney teaches a tube nut (208). Regarding claim 10, in view of Stoianovici, which teaches multiple thread starts, it would have been obvious to use two, three or four starts in the device of Mahoney as these overlap the range disclosed by Stoianovici. Regarding claim 11, Mahoney teaches a first drive mechanism (220a) and a second drive mechanism (220b). The first (220a) does not rotate the wheel (i.e. an increment of zero) and the second rotates the wheel (one tooth of rotation). Regarding claim 12, Mahoney teaches that the first mechanism indirectly rotates the lead screw (i.e. by providing a reset of the finger 222) and the second mechanism directly rotates the lead screw (by pulling a tooth with the finger 222). Regarding claim 13, Mahoney teaches that the lead screw is disposed on a right side of the plunger (see Fig. 3). Regarding claim 14, Mahoney teaches that the lead screw is coaxial with the piston (see Fig. 3). Claim(s) 3-4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mahoney in view of Stoianovici as applied to claim 1, and further in view of US Pre-Grant Publication 2018/0015228 to Stefanov et al. (Stefanov). Regarding claim 3, Mahoney teaches the limitations of claim 1 as discussed above, and further teaches a shape memory wire (220) and a spring engaging the pawl (122, “compression or other type”). Mahoney does not teach an ortho-planar spring. Stefanov teaches another medicament delivery device generally, and particularly teaches a locking device (80, 90, 110) including an ortho-planar spring (110). Stefanov teaches that this spring provides an axial bias and thereby allows for locking and unlocking of a linear travel device (paragraphs 70, 83). One of ordinary skill in the art would have found it obvious before the effective filing date of the application to use an ortho-planar spring as taught by Stefanov to the device of Mahoney to provide the desired bias. Regarding claim 4, Mahoney teaches a finger (222), a ratchet wheel (214), and a locking mechanism (244) at least indirectly fixed to the ortho-planar spring and having a tooth configured to mate with the ratchet wheel. The provision of multiple teeth would be obvious as the mere duplication of the illustrated tooth (244, see MPEP 2144.04 VI. B). Claim(s) 7 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mahoney in view of Stoianovici as applied to claim 1 above, and further in view of US Pre-Grant Publication 2021/0341036 to Mock et al. (Mock). Regarding claims 7 and 8, Mahoney teaches claim 1 as discussed above. Mahoney does not teach a clutch with a clamping torsion spring. Mock teaches a rotational clutch (320) configured to clamp around a drive shaft in response to a controller signal (paragraph 89) via a torsion spring (1165, paragraph 85). Mahoney teaches that this allows selective actuation of the shaft (paragraph 89). One of ordinary skill in the art would have found it obvious before the effective filing date of the application to provide a clutch as taught by Mock to the device of Mahoney in order to allow for selective actuation of the leadscrew thereof. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to PHILIP E STIMPERT whose telephone number is (571)270-1890. The examiner can normally be reached Monday-Friday, 8a-4p. 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, Chelsea Stinson can be reached at 571-270-1744. 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. /PHILIP E STIMPERT/Primary Examiner, Art Unit 3783 22 January 2026
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Prosecution Timeline

Aug 17, 2023
Application Filed
Jan 22, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12577961
LOW-FLOW FLUID DELIVERY SYSTEM AND LOW-FLOW DEVICE THEREFOR
2y 5m to grant Granted Mar 17, 2026
Patent 12573932
LINEAR MOTOR AND LINEAR COMPRESSOR
2y 5m to grant Granted Mar 10, 2026
Patent 12560168
VARIABLE DISPLACEMENT PUMP
2y 5m to grant Granted Feb 24, 2026
Patent 12560173
MOTOR AND APPARATUS USING THE SAME
2y 5m to grant Granted Feb 24, 2026
Patent 12529366
MEMBRANE PUMP
2y 5m to grant Granted Jan 20, 2026
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
63%
Grant Probability
99%
With Interview (+49.3%)
3y 9m
Median Time to Grant
Low
PTA Risk
Based on 857 resolved cases by this examiner. Grant probability derived from career allow rate.

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