Prosecution Insights
Last updated: April 19, 2026
Application No. 18/712,590

Walking Frame with Self-Aligning Wheels

Non-Final OA §103
Filed
May 22, 2024
Examiner
HAWK, NOAH CHANDLER
Art Unit
3636
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Nottingham Rehab Limited
OA Round
1 (Non-Final)
62%
Grant Probability
Moderate
1-2
OA Rounds
2y 0m
To Grant
84%
With Interview

Examiner Intelligence

Grants 62% of resolved cases
62%
Career Allow Rate
950 granted / 1545 resolved
+9.5% vs TC avg
Strong +22% interview lift
Without
With
+22.0%
Interview Lift
resolved cases with interview
Fast prosecutor
2y 0m
Avg Prosecution
62 currently pending
Career history
1607
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
41.2%
+1.2% vs TC avg
§102
34.7%
-5.3% vs TC avg
§112
22.1%
-17.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1545 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. Claims 1-10 are rejected under 35 U.S.C. 103 as being unpatentable over Rothstein et al. in US Publication 2014/0265256 in view of Vig et al. in US Patent 4054965. Regarding Claims 1-9, Rothstein teaches a walking frame comprising: a walking frame body (102) configured to provide support to a user as they walk across a surface; at least one swivel castor (108/110/112/114) coupled to the walking frame body and comprising: a wheel (108/110) configured to contact the surface and rotate as the user pushes the walking frame across the surface; and a wheel mount (112/114) rotatable with respect to the walking frame body to change the orientation of the wheel relative to the walking frame body and allow the user to steer the walking frame in different directions across the surface; and an alignment mechanism (510) configured to apply a biasing force to the wheel mount on rotation thereof to bias the wheel into a predetermined orientation relative to the walking frame body, Rothstein is silent on the use of a biasing force that decreases as the wheel swivels. Vig teaches a swivel castor including frame body (10), a wheel (11) configured to contact the surface and rotate as it is moved across the surface, and a wheel mount (12) rotatable with respect to frame body to change the orientation of the wheel relative to the walking frame body and allow the user to steer the frame in different directions across the surface; and an alignment mechanism (19/20/21) configured to apply a biasing force to the wheel mount on rotation thereof to bias the wheel into a predetermined orientation relative to the frame body, wherein the biasing force applied to the wheel mount decreases as the wheel mount rotates away from the predetermined orientation (magnetic force is well-known to decrease as the magnets are moved away from each other), wherein the alignment mechanism is configured to apply the biasing force to the wheel mount over a predetermined rotational range (when the magnets are near enough to interact) of the wheel mount, wherein the predetermined rotational range of the wheel mount is less than 360 degrees, wherein the alignment mechanism is configured to apply no biasing force to the wheel mount outside of the predetermined rotational range (such as when the wheel is at a 90 degree angle to the magnets 20 and 21), wherein the alignment mechanism comprises a plurality of magnets configured to provide the biasing force to bias the wheel mount into the predetermined orientation, wherein the alignment mechanism comprises a first magnet (20) coupled to the frame body and a second magnet (19) coupled to the wheel mount and configured to rotate therewith, wherein relative rotation between the wheel mount and the frame body causes the biasing force to be applied to the wheel mount, wherein opposing poles of the first and second magnets are aligned when the wheel mount is in the predetermined orientation (see Fig. 6), wherein the first and second magnets are coaxial when the wheel mount is in the predetermined orientation (see Fig. 4), wherein the first and second magnets are coupled to the walking frame body and the wheel mount respectively in a position offset from a rotational axis of the wheel mount (see Fig. 3). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Rothstein by using castors as taught by Vig in order to prevent unwanted swiveling of the castors when the device is off the ground, and to provide a positive alignment for the wheels to allow the user to more easily move straight. Regarding Claim 10, Rothstein, as modified, teaches a plurality of swivel castors (there are 4). Claims 1-11 are rejected under 35 U.S.C. 103 as being obvious over Obitts in US Patent 5692762 in view of Vig et al. in US Patent 4054965. Regarding Claims 1-9, Obitts teaches a walking frame comprising: a walking frame body (A) configured to provide support to a user as they walk across a surface; at least one swivel castor (62a/b) coupled to the walking frame body to allow the user to steer the walking frame in different directions across the surface; and an alignment mechanism (the wheels can be “fixed”) configured to apply a biasing force to the wheel mount on rotation thereof to bias the wheel into a predetermined orientation relative to the walking frame body, Obitts is silent on the use of a biasing force that decreases as the wheel swivels. Vig teaches a swivel castor including frame body (10), a wheel (11) configured to contact the surface and rotate as it is moved across the surface, and a wheel mount (12) rotatable with respect to frame body to change the orientation of the wheel relative to the walking frame body and allow the user to steer the frame in different directions across the surface; and an alignment mechanism (19/20/21) configured to apply a biasing force to the wheel mount on rotation thereof to bias the wheel into a predetermined orientation relative to the frame body, wherein the biasing force applied to the wheel mount decreases as the wheel mount rotates away from the predetermined orientation (magnetic force is well-known to decrease as the magnets are moved away from each other), wherein the alignment mechanism is configured to apply the biasing force to the wheel mount over a predetermined rotational range (when the magnets are near enough to interact) of the wheel mount, wherein the predetermined rotational range of the wheel mount is less than 360 degrees, wherein the alignment mechanism is configured to apply no biasing force to the wheel mount outside of the predetermined rotational range (such as when the wheel is at a 90 degree angle to the magnets 20 and 21), wherein the alignment mechanism comprises a plurality of magnets configured to provide the biasing force to bias the wheel mount into the predetermined orientation, wherein the alignment mechanism comprises a first magnet (20) coupled to the frame body and a second magnet (19) coupled to the wheel mount and configured to rotate therewith, wherein relative rotation between the wheel mount and the frame body causes the biasing force to be applied to the wheel mount, wherein opposing poles of the first and second magnets are aligned when the wheel mount is in the predetermined orientation (see Fig. 6), wherein the first and second magnets are coaxial when the wheel mount is in the predetermined orientation (see Fig. 4), wherein the first and second magnets are coupled to the walking frame body and the wheel mount respectively in a position offset from a rotational axis of the wheel mount (see Fig. 3). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Obitts by using castors as taught by Vig in order to prevent unwanted swiveling of the castors when the device is off the ground, and to provide a positive alignment for the wheels to allow the user to more easily move straight. Regarding Claim 10, Obitts, as modified, teaches a plurality of swivel castors (there are 2). Regarding Claim 11, Obitts, as modified, teaches that the walking frame body comprises front legs (22a/22b) and rear (24a/24b) legs, and wherein a swivel castor is coupled to each of the front legs and a low-friction glide (100) for sliding over the surface is coupled to each of the rear legs. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Cooper et al., Warncke et al., Foster, and EP 3081391 teach castor alignment devices Any inquiry concerning this communication or earlier communications from the examiner should be directed to NOAH C. HAWK whose telephone number is (571)272-1480. The examiner can normally be reached M-F 9am to 5:30pm. 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, David Dunn can be reached at 5712726670. 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. NOAH C. HAWK Primary Examiner Art Unit 3636 /Noah Chandler Hawk/Primary Examiner, Art Unit 3636
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Prosecution Timeline

May 22, 2024
Application Filed
Jan 28, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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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
62%
Grant Probability
84%
With Interview (+22.0%)
2y 0m
Median Time to Grant
Low
PTA Risk
Based on 1545 resolved cases by this examiner. Grant probability derived from career allow rate.

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