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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 3/7/2025 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
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.
Claims 1-2 and 9-10 are rejected under 35 U.S.C. 103 as being unpatentable over Robinson US 4131391 in view of Moran et al. US 4141664 and Chando et al. US 20220111959.
Regarding claim 1, Robinson discloses: A helicopter rotor head structure (Fig 3), comprising
a hub (20),
a holder (Fig 9: 105),
a bearing (120) and a pitch change mechanism (110),
wherein the hub is provided at a top of a main rotor mast (Fig 3: 20 is at a top of 23),
a connecting shaft is provided in the hub (Fig 9: 81),
an end of the connecting shaft extends to an outside of the hub and has the bearing sleeved thereon (81 holds bearings 121,122,123,124 on the end of 81 outside of the hub), and
an end of the holder facing away from a blade is sleeved on the bearing, and is rotationally connected to the connecting shaft (105 end away from the blade is on the bearings 121,122,123,124 and is connected to the shaft 81);
the bearing comprises an angular contact bearing (121, 123 and 122 are depicted as angular ball bearings) and a deep groove ball bearing (124 is depicted as ball bearings) which are provided in sequence in a length direction of the connecting shaft (bearings are in sequence), and
the deep groove ball bearing is provided near the end of the connecting shaft (bearing 124 is on the end of the shaft 81); and
the pitch change mechanism is connected to the holder (110 is connected to holder 105).
However, Robinson is silent as to:
a thrust roller bearing
an angular contact bearing, a thrust roller bearing and a deep groove ball bearing which are provided in sequence in a length direction of the connecting shaft,
the pitch change mechanism is sleeved on the main rotor mast, and is connected to the holder.
From the same field of endeavor, Moran teaches:
a thrust roller bearing (Fig 1: 38)
a thrust roller bearing and a deep groove ball bearing which are provided in sequence in a length direction of the connecting shaft (38 and 34 are in sequence).
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to have modified Robinson’s ball bearing’s to have a thrust elastomeric bearing adjacent to (in series) and replacing the ball bearing as taught by Moran to resist centrifugal loading on the blade (Col 5, line 22-30) which will increase the life of the blade.
The combination would result in: an angular contact bearing, a thrust roller bearing and a deep groove ball bearing which are provided in sequence in a length direction of the connecting shaft.
From the same field of endeavor, Chando teaches:
the pitch change mechanism is sleeved on the main rotor mast, and is connected to the holder (Fig 1: 60 is sleeved on mast 25 and is connected to 72).
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to have modified Robinson’s pitch change mechanism and link to teach the component connecting a movement arm to a swash plate around a mast that moves the holder as taught by Chando to have higher control authority to improve maneuverability and gust rejection capability and facilitate transition between different flight modes (Par 3).
Regarding claim 2, Robinson as modified by Moran and Chando in the rejection of claim 1, where Robinson discloses:
wherein the connecting shaft is provided in a direction perpendicular to an axial direction of the hub (Fi 9: 81 and is perpendicular to the axis of rotation of 20), and both ends of the connecting shaft extend to the outside of the hub, and the bearing and the holder are provided at two ends of the connecting shaft respectively (Fig 9 shows the repeated structure on the opposite side).
Regarding claim 9, Robinson as modified by Moran and Chando in the rejection of claim 1, where Chando teaches:
wherein the pitch change mechanism comprises a connecting seat (Fig 1: 60) and a pitch change tie rod (62), wherein the connecting seat is sleeved on the main rotor mast (60 is sleeved on 25),
one end of the pitch change tie rod is connected to the connecting seat (62 is attached to 60), and
the other end of the pitch change tie rod is connected to the holder (Other end of 62 is connected to the holder 72); and
the connecting seat is provided with a driving mechanism that is configured to drive the connecting seat to move up and down along the main rotor mast (60 is attached to 40).
Regarding claim 10, Robinson as modified by Moran and Chando in the rejection of claim 1, where Chando teaches:
a rocker arm (Fig 1: arm that comes off of 72) that is provided in a length direction of the holder, one end of the rocker arm being connected to the holder (Arm of 72 is attached to the holder 72), and
the other end of the rocker arm being connected to the end of the pitch change tie rod facing away from the connecting seat (Arm of 72 is attached to 62).
Allowable Subject Matter
Claims 3-8 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Regarding claim 3, Robinson as modified by Moran and Chando in the rejection of claim 1, where Robinson discloses:
wherein a sleeve is provided at the end of the holder connected to the connecting shaft (Fig 9: 105’s end is a sleeve), an annular flange is provided on an inner wall of the sleeve (125 can be considered a flange extending from the inner wall of the sleeve).
The combination of Robinson and Moran would result in:
an annular flange is located between the angular contact bearing and the thrust roller bearing when mounted (Robinson teaches the sleeve being located between a ball bearing and a series of bearings; Moran teaches a series of bearings containing a thrust bearing).
However, Moran does not teach
two sides of the annular flange abut against the angular contact bearing and the thrust roller bearing respectively.
This is considered allowable subject matter and would limit the arrangement of the order of the bearings. There was not prior found in the search that would teach a flange or sleeve being in-between and in contact/ abutting a contact bearing and thrust bearing.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Cravener US 20210354815, Laflamme et al. US 20180319489, Caldwell US 3207226, Doman et al. US 3007530, and Wittke et al. US 20200001992 discloses a similar multiple bearing structure as applicant. Paynton US 20160090178, Uebori US 20150321756, and Bammer US 20160031557 discloses a similar swash plate structure as applicant.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Andrew J Marien whose telephone number is (469)295-9159. The examiner can normally be reached 9:00 am- 6:00 pm CST, Monday through Friday.
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/Andrew J Marien/Primary Examiner, Art Unit 3745
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