Prosecution Insights
Last updated: April 19, 2026
Application No. 18/245,820

UNDERWATER SNAKE ROBOT WITH EXTREME LENGTH

Final Rejection §103
Filed
Mar 17, 2023
Examiner
LEE, BENJAMIN P
Art Unit
3641
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Eelume AS
OA Round
2 (Final)
80%
Grant Probability
Favorable
3-4
OA Rounds
2y 8m
To Grant
97%
With Interview

Examiner Intelligence

Grants 80% — above average
80%
Career Allow Rate
1004 granted / 1254 resolved
+28.1% vs TC avg
Strong +17% interview lift
Without
With
+17.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
25 currently pending
Career history
1279
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
47.6%
+7.6% vs TC avg
§102
31.4%
-8.6% vs TC avg
§112
14.8%
-25.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1254 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 . Response to Arguments Applicant’s response dated 8/4/2025 is acknowledged and appreciated. The arguments have been considered and are not persuasive. Applicant argues that the Pettersen prior art (US 2018/0021945) only teaches an underwater snake robot with a length that is at least five times its maximum or average width or more preferably, at least ten times its maximum or average width and that it would not merely be an obvious design modification to require a length-to-diameter ratio of at least 25:1 as claimed. Applicant indicates “that the claimed L:D ratio is not an arbitrary dimensional parameter, but rather yields demonstrable and non-obvious improvements in endurance and energy efficiency”. In response, Examiner asserts that the Petersen specification alludes to benefits related to a larger length-to-diameter ratio where it is stated that it is preferable to increase the overall length relative to width to “at least” ten times (par. 10) providing “greater length and range of movement”. In other words, it appears that the Petersen disclosure is indicating that a longer and narrower snake robot is desirable and will provide benefits. Examiner asserts that those of ordinary skill in the art would be motivated to decrease hydrodynamic form drag to increase efficiency of an underwater vehicle and streamlining or narrowing a vehicles shape is well known and common and would have been an obvious design modification. Examiner maintains that taking an existing underwater robot snake and making it more streamlined or narrower does not constitute being new and novel. 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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. 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. Claim(s) 1-12, 14, 15 and 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pettersen et al. (U.S. Patent Application Publication 2018/0021945) in view of Holmes et al. (U.S. Patent 6,973,893). In regards to claim 1, Pettersen et al (henceforth referred to as Pettersen) disclose an underwater snake robot for performing subsea operations, the robot comprising: a series of links that are connected to one another by one or more joint modules for allowing a flexural motion of the robot. Pettersen teaches multiple links (items 6 of Pettersen); an one or more thrust devices for applying thrust to the robot for propulsion and/or guidance. Pettersen teaches multiple types and locations of thrusters (par. 13 and tunnel or side thrusters, items 6 and 18); wherein the flexural motion and/or thrust device(s) enable movement of the robot and control of the orientation and/or location of the links, and wherein the robot has a length to diameter ratio of at least 25:1. The snake robot of Pettersen is capable of flexural motion using the thrusters and joints and although the length and/or ratio of length to width of the Pettersen device is not explicitly disclosed. However, Pettersen as well as other prior art discloses various lengths and widths except for the specifics of the claims. It would have been an obvious matter of design choice to make the ratio of the Pettersen snake robot’s length to width of any of various values including 25:1 as claimed, since such a modification would have involved a mere change in size of a component. A change in size is generally recognized as being within the level of ordinary skill in the art. In re Rose, 105 USPQ 237 (CCPA 1955); Petersen does not explicitly disclose that the cross-section of the robot, links of the robot and/or thrust devices fit within a diameter of less than 1 meter. However, Holmes et al (henceforth referred to as Holmes) teaches a snake-like submersible vehicle with dimensions similar to that claimed with lengths in the 80-200 meter range and with a 2 meter with and fabrication of the snake robot underwater vehicle of Petersen to various lengths and diameters including those claimed would have been an obvious matter of design choice, since such a modification would have involved a mere change in size of a component. A change in size is generally recognized as being within the level of ordinary skill in the art. In re Rose, 105 USPQ 237 (CCPA 1955). In regards to claim 2, Pettersen additionally does not disclose that the robot has a length to diameter ratio of at least 30:1, preferably at least 50:1 and more preferably at least 100:1. However, again, it would have been an obvious matter of design choice to make the ratio of the Pettersen snake robot’s length to width of any of various values including those claimed, since such a modification would have involved a mere change in size of a component. A change in size is generally recognized as being within the level of ordinary skill in the art. In re Rose, 105 USPQ 237 (CCPA 1955). In regards to claim 3, Pettersen does not explicitly disclose that the robot has length of at least 10m, preferably at least 15m and more preferably at least 20m. However, it would have been an obvious matter of design choice to make the ratio of the Pettersen snake robot’s length of any of various values including 10, 15 or 20 meters as claimed, since such a modification would have involved a mere change in size of a component. A change in size is generally recognized as being within the level of ordinary skill in the art. In re Rose, 105 USPQ 237 (CCPA 1955). In regards to claim 4, Pettersen discloses that the robot comprises an accessory, or a connection point for an accessory, attached to the robot. Note that Pettersen teaches that the robot may include different tools or accessories including sensors, cameras or manipulators (items 14). In regards to claim 5, Pettersen discloses that the robot comprises multiple accessories, or connection points for accessories, attached to the robot at different points along the length of the robot. Pettersen teaches at least different locations for manipulators (items 14) and/or inspection tools (items 12). In regards to claim 6, Pettersen discloses that the robot comprises at least one battery module. Pettersen teaches battery power (par. 96). In regards to claims 7 and 8, Pettersen teaches a battery connected to the snake robot, but fails to disclose that the robot comprises multiple battery modules located at different points along the length the of the robot, or that the robot comprises at least two battery modules, preferably at least three battery modules and more preferably at least five battery modules. However, it would have been obvious to one having ordinary skill in the art at the time the invention was made to provide any number of batteries in/on the Pettersen device to allow for additional power and, since it has been held that mere duplication of the essential working parts of a device involves only routine skill in the art. St. Regis Paper Co. v. Bemis Co., 193 USPQ 8. In regards to claim 9, Pettersen discloses that the battery modules(s) is interchangeable so that it can be replaced with another battery module when necessary, since the battery or batteries of the device are capable of being replaced/exchanged. In regards to claim 10, Pettersen discloses that the diameter of the robot is substantially constant across the joint modules, wherein the diameter of the series of links and joint modules are preferably approximately equal and wherein the diameter of the robot is preferably substantially constant along its length. Pettersen illustrates embodiments with substantially consistent diameter through the modules and joints as shown in figure 5. In regards to claim 11, Pettersen discloses one or more shrouds that ensure the diameter of the robot is substantially constant across the joint modules. Figure 10 illustrates shrouds joining modules to maintain constant diameter. In regards to claim 12, Pettersen discloses a connector for connecting one end of the robot to a winch system. The Pettersen snake robot includes a grasper that constitutes a connector that is capable of connecting to a winch system. In regards to claim 14, Pettersen discloses a method for control of an underwater snake robot as claimed in claim 1, the method comprising: controlling the thrust device(s) and/or the joint modules in order to move the robot into a required orientation and/or location; wherein the thrust device(s) and/or the joint modules are used to generate a flexural motion and adjust the shape and configuration of the robot; and wherein the thrust device(s) are used to move all of or parts of the robot in translation and/or in rotation. Pettersen teaches controlling the snake robot of previous claims in the manner claimed. In regards to claim 15, Pettersen discloses a method for control of an underwater snake robot as claimed in claim 14, wherein the method comprises: adjusting the shape of the robot into a linear configuration for reduced drag parallel to its axis; and applying thrust along the length of the robot parallel to its axis using the thrust device(s) in order to move the entire robot in translation. Pettersen illustrates at least a time when the snake robot has its modules aligned to form a linear shape (see figure 2. In regards to claim 16, Pettersen discloses a computer programme product comprising instructions that when executed on a data processing device will configure the data processing device to control an underwater snake robot claimed in claim 1 comprising: controlling the thrust device(s) and/or the joint modules in order to move the robot into a required orientation and/or location; wherein the thrust device(s) and/or the joint modules are used to generate a flexural motion and adjust the shape and configuration of the robot; and wherein the thrust device(s) are used to move all of or parts of the robot in translation and/or in rotation. Pettersen teaches a computer program that instructs the snake robot to perform the previously claimed maneuvers. Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pettersen et al. (U.S. Patent Application Publication 2018/0021945) and Holmes et al. (U.S. Patent 6,973,893) as applied to claim 12, and in further view of Jun et al. (Korean Patent Document KR20130068430). In regards to claim 13, Pettersen fails to disclose that the connector comprises a rope, line or tether that is configured to float when it is released from the robot. However, Jun et al (henceforth referred to as Jun) teaches a remote underwater vehicle connected via a tether that is capable of floating and it would have been obvious to one of ordinary skill in the art at the time of Applicant’s invention to provide a tether connected to the snake robot of Pettersen as taught by Jun, to allow the snake robot to be easily retrieved. Allowable Subject Matter Claims 17-20 are allowed. The following is a statement of reasons for the indication of allowable subject matter: With respect to claim 17, the closest prior art fails to teach or make obvious, including all the limitations of claim 17 and the base claim, that the robot is coiled around the rotatable drum when in a stored configuration. Summary/Conclusion Claims 1-16 are rejected and claims 17-20 are allowable. THIS ACTION IS MADE FINAL. 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 extension fee 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 BENJAMIN P LEE whose telephone number is (571)272-8968. The examiner can normally be reached between the hours of 8:30am and 5:00pm on Monday through Friday. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Troy Chambers can be reached on 571-272-6874. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). /BENJAMIN P LEE/Primary Examiner, Art Unit 3641
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Prosecution Timeline

Mar 17, 2023
Application Filed
Aug 03, 2025
Non-Final Rejection — §103
Oct 30, 2025
Response Filed
Feb 03, 2026
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

3-4
Expected OA Rounds
80%
Grant Probability
97%
With Interview (+17.0%)
2y 8m
Median Time to Grant
Moderate
PTA Risk
Based on 1254 resolved cases by this examiner. Grant probability derived from career allow rate.

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