Prosecution Insights
Last updated: April 19, 2026
Application No. 18/331,337

Arrangement of a mowing head, an output shaft for receiving a mowing head and a fastening device for fixing the mowing head on the output shaft, and work apparatus with such an arrangement

Final Rejection §103§112
Filed
Jun 08, 2023
Examiner
DONG, LIANG
Art Unit
3724
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Andreas Stihl AG & Co. KG
OA Round
2 (Final)
52%
Grant Probability
Moderate
3-4
OA Rounds
3y 1m
To Grant
84%
With Interview

Examiner Intelligence

Grants 52% of resolved cases
52%
Career Allow Rate
250 granted / 480 resolved
-17.9% vs TC avg
Strong +32% interview lift
Without
With
+32.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
68 currently pending
Career history
548
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
51.6%
+11.6% vs TC avg
§102
21.0%
-19.0% vs TC avg
§112
25.4%
-14.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 480 resolved cases

Office Action

§103 §112
DETAILED ACTION Response to Amendment The Amendment filed 11/12/2025 has been entered. Claims 1-18 remain pending in the application. Claims 10-11 were withdrawn. Claim Rejections - 35 USC § 112(d) The following is a quotation of 35 U.S.C. 112(d): (d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers. The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph: Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers. Claim 18 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Examiner notes that the limitation of “wherein the actuating element (24) is formed separately of the mowing head (3)” was already added in amended claim 1, which claim 18 depends upon, thus claim 18 fails to further limit the device. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements. 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 1-9 and 14-16 are rejected under 35 U.S.C. 103 as being unpatentable over Underwood (US 20170095131 A1) in view of Nakanishi (US 4504167). Regarding claim 1, Underwood teaches an assembly, comprising: a mowing head (40, see Figure 5), an output shaft (20) for receiving the mowing head (see Figure 4), and a fastening device (48 with 24 and 46) for fixing the mowing head on the output shaft (see Figure 4), wherein the output shaft can be driven to rotate about an axis of rotation (see Figure 4), wherein the assembly has an anti-rotation lock (shape of 20 and 46) and an axial lock (24), wherein the mowing head is held corotatingly on the output shaft by the anti-rotation lock (see Figure 4), wherein the axial lock, in a blocking position, positively secures the mowing head on the output shaft against relative movement along the axis of rotation of the output shaft and, in an inoperative position, releases the mowing head for detachment from the output shaft (see Figures 1 and 5). Underwood fails to teach wherein the fastening device comprises an actuating element accessible to an operator, the axial lock being switchable into the blocking position and into the inoperative position by means of the actuating element, wherein the actuating element is formed separately of the mowing head. Nakanishi teaches a connection assembly including a fastening device (assembly of 20 and 10, see Figure 2) comprises an actuating element (7) accessible to an operator, the axial lock being switchable into the blocking position and into the inoperative position by means of the actuating element (position and with arrow 24 position of 4, see Figure 1). It would have been obvious to one of ordinary skill in the art to modify the device of Underwood to change the fastening device, as taught by Nakanishi, in order to make a quick and long lasting connection (col. 1 lines 5-41 of Nakanishi). Modified Underwood still fails to teach the actuating element is formed separately of the mowing head. As disclosed the modified Underwood teaches the actuating element is formed on the mowing head. It would have been obvious to one having ordinary skill in the art to further modify the device of modified Underwood to have reversed the location of the fasten elements and have the actuating element formed separately of the mowing head (i.e. on the tool). Since it has been held that rearranging parts of an invention involves only routine skill in the art. In re Japikse, 86 USPQ 70. MPEP 2144.04 VI. C. Regarding claim 2, modified Underwood further teaches the anti-rotation lock is designed as a positive connection (see Figure 5 of Underwood). Regarding claim 3, modified Underwood further teaches the mowing head can be attached to and detached from the output shaft without tools (as modified, remove via 7 of Nakanishi, see Figure 2 of Nakanishi). Regarding claim 4, modified Underwood further teaches the axial lock comprises a holding contour and a locking contour (as modified, 3 and 6 of Nakanishi, see Figure 2 of Nakanishi), and wherein the holding contour engages the locking contour in the blocking position of the axial lock (as modified, 3 and 6 of Nakanishi, see Figure 2 of Nakanishi). Regarding claim 5, modified Underwood further teaches the holding contour is designed to be radially displaceable with respect to the axis of rotation of the output shaft by the actuating element (as modified, 3 and 6 of Nakanishi, see Figure 2 of Nakanishi). Regarding claim 6, modified Underwood further teaches the holding contour is part of the fastening device, and wherein the locking contour is formed on the mowing head (as modified, 3 and 6 of Nakanishi, see Figure 2 of Nakanishi). Regarding claim 7, modified Underwood further teaches the holding contour is part of the mowing head, and wherein the locking contour is formed on the output shaft (as modified, 3 and 6 of Nakanishi, see Figure 2 of Nakanishi). Regarding claim 8, modified Underwood further teaches the holding contour is formed on a slide frame (as modified, 4 of Nakanishi, see Figure 2 of Nakanishi). Regarding claim 9, modified Underwood further teaches the slide frame comprises an opening (5 of Nakanishi), and wherein the locking contour is arranged in the opening of the slide frame (as modified, see Figure 2 of Nakanishi). Regarding claim 14, Underwood teaches the assembly comprises a spring element, and wherein the spring element is operatively connected to the holding contour in such a way that the holding contour is clamped into the locking contour (as modified, spring 8 of Nakanishi, see Figure 2 of Nakanishi). Regarding claim 15, Underwood teaches an assembly, comprising: a mowing head (40, see Figure 5), an output shaft (20) for receiving the mowing head (see Figure 4), and a fastening device (48 with 24 and 46) for fixing the mowing head on the output shaft (see Figure 4), wherein the output shaft can be driven to rotate about an axis of rotation (see Figure 4), wherein the assembly has an anti-rotation lock (shape of 20 and 46) and an axial lock (24), wherein the mowing head is held corotatingly on the output shaft by the anti-rotation lock (see Figure 4), wherein the axial lock, in a blocking position, positively secures the mowing head on the output shaft against relative movement along the axis of rotation of the output shaft and, in an inoperative position, releases the mowing head for detachment from the output shaft (see Figures 1 and 5). Underwood fails to teach wherein the fastening device comprises an actuating element accessible to an operator, the axial lock being switchable into the blocking position and into the inoperative position by means of the actuating element, the axial lock comprises a holding contour and a locking contour, and wherein the holding contour engages the locking contour in the blocking position of the axial lock, a latching unit, wherein the latching unit comprises the actuating element, the holding contour, and all components by which the holding contour and the actuating element are operatively connected to one another, wherein a center of mass of the latching unit lies outside the axis of rotation in such a way that, during operation of the assembly, centrifugal forces acting on the latching unit reinforce a clamping of the holding contour against the locking contour in the blocking position, and wherein the centrifugal forces action on the latching unit are caused by rotation of the latching unit about an axis of rotation of the output shaft in an area of the mowing head. Nakanishi teaches a connection assembly including a fastening device (assembly of 20 and 10, see Figure 2) comprises an actuating element (7) accessible to an operator, the axial lock being switchable into the blocking position and into the inoperative position by means of the actuating element (position and with arrow 24 position of 4, see Figure 1). It would have been obvious to one of ordinary skill in the art to modify the device of Underwood to change the fastening device, as taught by Nakanishi, in order to make a quick and long lasting connection (col. 1 lines 5-41 of Nakanishi). The resulting device of modified Underwood teaches the axial lock comprises a holding contour and a locking contour (as modified, 3 and 6 of Nakanishi, see Figure 2 of Nakanishi), and wherein the holding contour engages the locking contour in the blocking position of the axial lock (as modified, 3 and 6 of Nakanishi, see Figure 2 of Nakanishi), a latching unit (as modified, 4 of Nakanishi), wherein the latching unit comprises the actuating element, the holding contour, and all components by which the holding contour and the actuating element are operatively connected to one another, wherein a center of mass of the latching unit lies outside the axis of rotation in such a way that, during operation of the assembly, centrifugal forces acting on the latching unit reinforce a clamping of the holding contour against the locking contour in the blocking position (as modified, 4 is offset from the center of 1, see Figure 2 of Nakanishi), and wherein the centrifugal forces action on the latching unit are caused by rotation of the latching unit about an axis of rotation of the output shaft in an area of the mowing head (as modified, with the added latch unit in the mowing head like the fastener in Underwood). Regarding claim 16, Underwood teaches a handheld work apparatus comprising the assembly according to claim 1 (see Figure 5 of Underwood). Claims 12-13 and 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Underwood (US 20170095131 A1) in view of Nakanishi (US 4504167) and in further view of Lauciello (US 20210170565 A1). Regarding claim 12, modified Underwood further teaches the fastening device comprises a one-piece base body (as modified, see Figure 2 of Nakanishi) Modified Underwood fails to teach a fan wheel is formed on the base body of the fastening device. Lauciello teaches a trimmer with a fan wheel at the connection of the trimmer head. It would have been obvious to one of ordinary skill in the art to modify the device of Underwood to add the fan wheel at the connection, as taught by Lauciello, in order to better cool the motor and the trimmer (abstract of Lauciello). Regarding claim 13, modified Underwood further teaches the base body has a receiving pocket (as modified by Nakanishi, space for 4, see Figure 2 of Nakanishi), and wherein the actuating element of the fastening device is held in the receiving pocket (as modified, see Figure 2 of Nakanishi). Regarding claim 17, modified Underwood further teaches wherein the actuating element is arranged in the fan wheel (as modified in claim 1 and 12, both the actuating element and the fan wheel are added to the head portion of the tool that is not the spinning mowing head, as the fan wheel is added include the portion that the connection rod is in, the actuating element is interpreted as arranged in the fan wheel). Regarding claim 18, modified Underwood further teaches wherein the actuating element is formed separately of the mowing head (in the same modification as claim 1). Response to Arguments Applicant's arguments filed 11/12/2025 have been fully considered but they are not persuasive. In response to applicant's argument that Underwood fails to teach the actuating element is formed separately of the mowing head. Examiner notes that new modification was added to teach the new limitation. In response to applicant's argument that Nakanishi fail to teach the device spinning. Examiner notes that once the actuating element arrangement is added to the mowing head, which is the spinning portion of the device, thus cause the centrifugal force acting on the latching unit in the same way with respect to the axis, thus meeting the limitation. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 nonprovisional extension fee (37 CFR 1.17(a)) 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 LIANG DONG whose telephone number is (571)270-0479. The examiner can normally be reached Monday - Thursday 8 AM-6 PM. 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, Ashley Boyer can be reached at 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 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. /LIANG DONG/Examiner, Art Unit 3724 2/19/2026
Read full office action

Prosecution Timeline

Jun 08, 2023
Application Filed
Jul 10, 2025
Non-Final Rejection — §103, §112
Nov 12, 2025
Response Filed
Feb 19, 2026
Final Rejection — §103, §112 (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

3-4
Expected OA Rounds
52%
Grant Probability
84%
With Interview (+32.2%)
3y 1m
Median Time to Grant
Moderate
PTA Risk
Based on 480 resolved cases by this examiner. Grant probability derived from career allow rate.

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