DETAILED ACTION
1. This action is in response to applicant's amendment received on 10/3/2025. Amended claims 1 and 5 are acknowledged and the following grounds of rejection below are maintained. Claim 6 is cancelled.
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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 3/9/2026 has been entered.
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.
Claim(s) 1-5 and 7-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Suzuki et al. (US Publication 2017/0314502), hereinafter “Suzuki”.
Regarding claim 1, Suzuki discloses the claimed invention such as an internal combustion engine comprising: a piston (18); a cylinder (20) that has a sliding surface on which the piston slides; and a piston pin that connects the piston and a connecting rod (paragraph 41), wherein the sliding surface has a shape in which an inner diameter of a central portion, which is central in an axial direction, is larger than an inner diameter of an upper end portion facing the piston positioned at a top dead center (shown in figure 1, paragraphs 53-54), the sliding surface has a lower end portion facing the piston positioned (shown in figure below) at a bottom dead center, and a length of the upper end portion (any portion of the sliding surface around TDC) in the axial direction is larger than a length of the lower end portion in the axial direction (since examiner notes that he can choose which portion can the upper and which portion can be the lower since the claims nor the specification define these portions, examiner can choose the upper end portion to have a larger length than the lower end portion), but is silent to disclose the piston pin being located in the center of the piston. It would have been obvious to one having ordinary skill in the art before the effective filing date of when the invention was made to have the piston pin be located in the center of the piston since it was known in the art that central location allows for piston balancing with less force on the cylinder wall with an off-center location. Examiner notes that nothing in the claims mentions the diameter of the lower end portion. Examiner also notes that the claim does not require that the diameter remain the same through each of the portions. Examiner can pick and choose the different portion as shown in the figure below as the length of the upper end portion is larger than the length of the lower end portion.
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Regarding claim 2, Suzuki discloses the internal combustion engine according to claim 1, wherein the central portion of the sliding surface is convexly curved (20C) between the upper end portion (shown in figure above) and the lower end portion (shown in figure above) of the sliding surface near a bottom dead center of the piston (paragraph 52).
Regarding claim 3, Suzuki discloses the internal combustion engine according to claim 1, wherein the central portion of the sliding surface is curved in an arc shape between the upper end portion (shown in figure above) and the lower end portion (shown in figure above) of the sliding surface near a bottom dead center of the piston (paragraph 52). Figure 1 shows a curved or arc shape of the cylinder wall.
Regarding claim 4, Suzuki discloses the internal combustion engine according to claim 1, wherein the upper end portion (shown in figure above) faces an entire outer peripheral surface of the piston (18) positioned at the top dead center (shown by dashed lines in figure 1).
Regarding claim 5, Suzuki discloses the internal combustion engine according to claim 1, wherein the inner diameter of the central portion is larger than an inner diameter (Ds) of the lower end portion (shown in figure 4).
Regarding claim 7, Suzuki discloses the internal combustion engine according to claim 1, wherein the piston includes a skirt portion (38) and a ring member (ring in groove 44) that is provided on an outer peripheral surface of the piston and scrapes off lubricating oil adhering to the sliding surface (paragraph 45), the cylinder includes a thrust region against which the skirt portion is pressed when the piston descends, the skirt portion includes a first opposing portion facing the thrust region, and a hole portion (groove 44) having a predetermined depth into which the lubricating oil scraped off by the ring member flows is provided at a center in a circumferential direction of the first opposing portion. Examiner notes that the claim does not state that the ring groove can’t be the hole portion or that the hole portion is separate or deeper than the groove. Therefore, the groove can functionally be considered the hole portion according to this broad claim.
Regarding claim 8, Suzuki discloses the internal combustion engine according to claim 1, wherein the piston includes a skirt portion and a ring member that is provided on an outer peripheral surface of the piston and scrapes off lubricating oil adhering to the sliding surface, the cylinder includes an anti-thrust region against which the skirt portion is pressed when the piston ascends, the skirt portion includes a second opposing portion facing the anti-thrust region (shown in figures 1 and 2), and a hole portion (44) having a predetermined depth into which the lubricating oil scraped off by the ring member flows is provided at the center of the second opposing portion in the circumferential direction. Examiner notes that the claim does not state that the ring groove can’t be the hole portion or that the hole portion is separate or deeper than the groove. Therefore, the groove can functionally be considered the hole portion according to this broad claim.
Regarding claim 9, Suzuki discloses the internal combustion engine according to claim 7, wherein the lubricating oil that has flowed into and is held by the hole portion (44) flows out to the skirt portion when the piston moves up and down (oil will flow out of an oil ring groove when the piston goes up and down).
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Suzuki in view of Watanabe et al. (US Patent 5,894,824), hereinafter “Watanabe”.
Regarding claim 10, Suzuki discloses the same invention substantially as claimed but is silent to provide a communication groove. However, Watanabe teaches a communication taper (111) below the oil ring groove (105, shown in figure 9) for the purpose of making the inclination of the piston smaller to ensure piston rotation with a reduced angle to provide less kinetic energy of the piston and reducing hammering (column 6, lines 43-58). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify Suzuki by incorporating a communication groove as taught by Watanabe for the purpose of making the inclination of the piston smaller to ensure piston rotation with a reduced angle to provide less kinetic energy of the piston and reducing hammering.
Response to Arguments
Applicant's arguments filed 10/3/2025 have been fully considered but they are not persuasive. Applicant argues that Suzuki does not recite the lengths being different for the upper end portion and lower end portion. However, examiner shows in figure provided above that a larger length of the upper end portion can be chosen compared to the lower end portion since claims do not mention otherwise.
Applicant argues that Suzuki doesn’t pay attention to the rocking of the piston and that the present application focuses on the upper end portion diameter to be larger. However, the claims do not mention the rocking of the piston prevention and examiner can pick a portion of the upper end that is larger in length than a portion of the bottom end since claims do not define these portions in any more detail.
Examiner notes that the limitation of “near” should be taken out and additional structure should be provided to rightfully exemplify figure 3 of the present invention in more details.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Refer to PTO-892.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SYED O HASAN whose telephone number is (571)272-0990. The examiner can normally be reached Monday-Friday; 11AM-7PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Lindsay Low can be reached at (571) 272-1196. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/SYED O HASAN/ Primary Examiner, Art Unit 3747 4/30/2026
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