Prosecution Insights
Last updated: April 19, 2026
Application No. 18/894,124

TRIMMER HEAD

Non-Final OA §112
Filed
Sep 24, 2024
Examiner
PAYER, HWEI-SIU C
Art Unit
3724
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Greenworks (Jiangsu) Co. Ltd.
OA Round
1 (Non-Final)
74%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
99%
With Interview

Examiner Intelligence

Grants 74% — above average
74%
Career Allow Rate
1064 granted / 1444 resolved
+3.7% vs TC avg
Strong +31% interview lift
Without
With
+30.6%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
32 currently pending
Career history
1476
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
39.8%
-0.2% vs TC avg
§102
16.8%
-23.2% vs TC avg
§112
35.2%
-4.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1444 resolved cases

Office Action

§112
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 Rejection - 35 U.S.C. 112(b) 1. 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. 2. Claims 7-9 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. (1) In claim 7, line 2 and 4, “a first end of the main body” and “a second end of the main body” are vague. Are they in addition to “one end of the main body” cited at line 10 of claim 1? As the disclosed invention is understood, the main body 61 has two ends, namely a first end (e.g., an upper end as shown in Fig.7) connected to a driving shaft (not shown) of a driving component (may be a gear box or a motor, see paragraph [0028] of the specification) and a second end (e.g., a lower end opposite the upper end). Thus, one of a first end and a second end has to refer back to “one end” cited in claim 1 so that the main body has two ends and not three ends. It is suggested “one end”, cited at line 10 of claim 1, be changed to --a first end--. Also, at lines 2 and 4 of claim 7, “a first end” and “a second end” should read --a second end-- and --the first end--, respectively. (2) In claim 8, lines 1-2, “the first end” should read --the second end-- in light of the above suggestion to amend claim 7. Indication of Allowable Subject Matter 1. Claims 1-6 and 10 are allowed. 2. Claims 7-9 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) set forth in this Office action. 3. Claims 1-10 contain allowable subject matter because none of the prior art of record taken alone or in combination thereof shows or fairly suggests the claimed trimmer head (100) comprising, among other things, a base (1) and a bump head (2) connected to the base (1, see Fig.1 below), a locking insert (6, see Fig.2 below) fixed in the base (1) and the bump head (2) and having one end passing through the base (1) and connectable to the driving shaft, wherein the locking insert (6) comprises a main body (61, see Fig.7 below) and a nylon sleeve (62) press-fitted inside the main body (61) and fixed thereto, such that when the drive shaft is screwed into the nylon sleeve (62) from one end of the main body (61), the driving shaft is connectable to the trimmer head (100) through the nylon sleeve (62). PNG media_image1.png 204 778 media_image1.png Greyscale PNG media_image2.png 616 370 media_image2.png Greyscale PNG media_image3.png 466 556 media_image3.png Greyscale The novelty of the claimed invention is the nylon sleeve (62) that locks the driving shaft such that the trimmer head (100) will not fall off the driving shaft (see paragraph [0032] of the specification). The trimmer head (100) can quickly remove tangled lawns through a reversing function without the trimmer head (100) falling off the driving shaft. Prior Art Citations The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. U.S. Patent No. 2,708,820 shows a grass trimmer quipped with an anti-tangle cutter. U.S. Patent No. 3,826,068 shows a grass trimmer comprising an insert (47) connected to a driving shaft (40) that drives the trimmer. U.S. Patent 4,097,991 shows a trimmer head (20) comprising a drive pin (42) having a threaded mating hole (61) for receiving a threaded portion of a drive shaft (84) to drive a spool (40) of the trimmer head (20). U.S. Patent No. 5,806,192 shows a grass trimmer head (10) comprising a lock nut (74) for preventing a drive shaft (30) from falling off the trimmer head e(10). U.S. Patent No. 6,901,667 shows a grass trimmer head (10) comprising a base (14), a bump head (81) connected to the base (14), and an insert (24) fixed in the base (14) and passing therethrough to be connected to a drive shaft (12), wherein the insert (24) has a threaded structure (24d, see Fig.8) for threaded engagement with the drive shaft (12), a squared head portion (24a) inter-fitting in a square upper portion (36) of the base (14), a cylindrical-shaped main body (24b) extending through and projects from a lower hexagonal portion (40, Fig.2) of the base (14). U.S. Patent No. 8,464,431 shows a trimmer head (see Fig.2) comprising an output shaft (23) having a hexagonal connector portion (34) received in a hexagonal aperture (40) formed in a base (24) of the trimmer head for driving the trimmer head, and a locking nut (91) threadably received in the output shaft (23) for preventing the trimmer head falling off the output shaft (23). U.S. Patent No. 9,883,628 is cited to show an anti-winding assembly for a trimmer head (see the abstract). CN 111972114 shows an output shaft anti-weed winding structure for a lawn mower. Point of Contact Any inquiry concerning this communication or earlier communications from the examiner should be directed to HWEI-SIU PAYER whose telephone number is (571)272-4511. The examiner can normally be reached on Monday – Friday from 6:00 AM to 2:00 PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Boyer Ashley, can be reached at telephone number 571-272-4502. 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 Patent Center. Status information for published applications may be obtained from Patent Center. Status information for unpublished applications is available through Patent Center to authorized users only. Should you have questions about access to the USPTO patent electronic filing system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). Examiner interviews are available via a variety of formats. See MPEP § 713.01. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) Form at https://www.uspto.gov/InterviewPractice. /HWEI-SIU C PAYER/ Primary Examiner, Art Unit 3724
Read full office action

Prosecution Timeline

Sep 24, 2024
Application Filed
Feb 17, 2026
Non-Final Rejection — §112 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12600054
HYBRID SAW BLADE
2y 5m to grant Granted Apr 14, 2026
Patent 12600051
RAZOR ASSEMBLY
2y 5m to grant Granted Apr 14, 2026
Patent 12589511
FOLDING KNIFE WITH REPLACEABLE BLADE
2y 5m to grant Granted Mar 31, 2026
Patent 12582252
Spoon Straw Digit Support Utensil
2y 5m to grant Granted Mar 24, 2026
Patent 12582211
SINGLE BLADE NAIL CUTTER
2y 5m to grant Granted Mar 24, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

1-2
Expected OA Rounds
74%
Grant Probability
99%
With Interview (+30.6%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 1444 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month