DETAILED CORRESPONDENCE
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 2/4/2026 has been entered.
Claim Rejections - 35 USC § 112
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter, which the applicant regards as his invention.
Claims 1-3 and 9-17 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Claim 1 recites, “the metallic portion is provided as a metal sheet”. Previously recited was “the piston wall comprises… a metallic portion” and “the piston base comprising a metallic portion”. It is unclear which metallic portion is being referred to.
Claim 1 recites, “the metallic portion includes… a bent portion”. Previously recited was “the piston wall comprises… a metallic portion” and “the piston base comprising a metallic portion”. It is unclear which metallic portion is being referred to.
Dependent claims not specifically mentioned are rejected due to dependency on a rejected base claim for failing to cure the deficiencies of the base claim.
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 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-3 and 9-17 are rejected under 35 U.S.C. 103 as being unpatentable over Rueckert et al. (EP 0847507 B1) in view of Reuss (U.S. 2018/0094681).
Regarding claim 1, Rueckert discloses (figs. 4-5) A piston (1) for a brake system (background at least), the piston having a first end (bottom) configured to engage with a brake fluid and a second end (top) configured to engage with a brake pad (see claims), and
a piston wall (see annotated figure) surrounding a cavity (4) of the piston between the first end and the second end, wherein the piston wall comprises a plastic portion (see claims at least) and a metallic portion (see abstract at least), and
wherein a piston base (see annotated figure) is provided at the first end of the piston, which piston base closes the piston at the first end (as shown), the piston base comprising a metallic portion (portion of 11 in the base) which is configured to contact the brake fluid (as shown);
wherein the plastic portion comprises a first plastic portion (see annotated figure, curved section) facing the cavity and a second plastic portion forming an outer hull of the piston wall (see annotated figure), and wherein the metallic portion is provided as a metal sheet (“U-shaped sheet metal strip 11”) disposed between the first plastic portion and the second plastic portion (as shown), and
wherein the metallic portion includes, at the second end of the piston, a bent portion (19) formed to contact the brake pad during braking “The degrees 19 of the U-shaped sheet metal strip are angled and form the contact surface of the insert part to not shown Brake pad”).
Rueckert does not appear to disclose the metallic portion of the piston wall and the metallic portion of the piston base being formed as separate pieces that contact one another. Reuss teaches (pgh. 0040 and fig. 4) a piston (10) with a plastic portion (pgh. 0035) and a metallic core member 16, the core member having a metallic portion of the piston base (closed end support portion 26) and a metallic portion of the piston wall (core cylindrical wall), where the core cylindrical wall and closed end support portion are separate pieces contacting one another (pgh. 0040: “The core cylindrical wall may be separate from, adjacent to, connected to, or integral with the closed end support portion.”).
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Annotated fig. 4 of Rueckert showing piston wall, base, and first and second plastic portions.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided the metallic portion of the piston wall and the metallic portion of the piston base as separate pieces contacting one another to fine tune the material properties for each section to optimize strength, weight and cost. For example, it may be desirable for the wall to have a larger compressive strength than the base, as the wall has a smaller surface area to transfer the brake force to the brake pad as compared to the entire back surface of the base exposed to the brake fluid. Accordingly, it may be desirable to construct the metallic portion of the wall out of steel, while the metallic portion of the base is made of aluminum, as this portion requires less compressive strength, but a benefit is achieved of minimizing weight of the piston. Further, it is noted that the modification amounts to constructing a formerly integral structure into various separate pieces, which has been held to involve only routine skill in the art. Nerwin v. Erlichman, 168 USPQ 177, 179.
Regarding claim 2, Rueckert does not appear to disclose the shape of the metallic portion at the piston base. In the same field of endeavor of metallic inserts for brake cylinders, Reuss teaches (see figs. 5a-5b) a metallic insert (16) including sidewalls (28) and a base 26 in the shape of a disc (as shown). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have changed the shape of the metallic base portion to disk shaped to increase the structural rigidity of the base portion of the piston due to the added metallic material of the base, since this area directly experiences hydraulic pressure from the system. Further, it is noted that this modification amounts to a mere change in shape, which has been held to be a design consideration within the level of ordinary skill in the art. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Regarding claim 3, Rueckert discloses (fig. 4) the piston base comprises a plastic portion (2) which is arranged at an inner side of the metallic portion of the base plate, facing the cavity (as shown).
Regarding claim 9, Rueckert discloses (fig. 4) the piston wall comprises one or more plastic portions and one or more metallic portions (the piston wall contains one of each), forming shells arranged in the plastic portions (one shell layer as metallic and one shell layer of plastic, as shown) and the metallic portions being arranged in alternating fashion (first the metallic portion is on the inside, and then it “alternates” to the plastic portion on the outside).
Regarding claim 10, Rueckert does not appear to disclose the thickness of each layer of the wall. Reuss teaches a brake piston 10 having a core portion (metallic portion) of “about 1mm” or “about 2 mm” (pgh. 0041), and a total wall thickness of “about 5 mm” (pgh. 0029), where if the core is 1mm and the wall is 5mm, then the plastic portion is 4mm, and if the core is 2mm thick, then the plastic portion is 3mm thick. Under both instances, each layer has a thickness of 1-4mm as claimed. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have made each layer 1-4mm thick to allow for appropriate strength and structural rigidity of the piston wall under axial load while compressing the brake, while still allowing for ease of manufacturing through stamping. For example, if the wall is too thin, it could bend radially when pressed against the brake pad. Alternatively, if the wall is too thick the device becomes unnecessarily heavy. It is additionally noted that such a modification amounts to a mere change in size of a known element, which has been held to involve only routine skill in the art. In re Rose, 105 USPQ 237 (CCPA 1955).
Regarding claim 11, Rueckert discloses (fig. 4) a geometric feature (20) is provided between the metallic portion of the piston wall and the plastic portion of the piston wall (radially between, as shown).
Regarding claim 12, Rueckert does not appear to disclose different metals for the base and wall, or different thermal expansion coefficients. Reuss teaches a core member having a closed end support portion (in the piston base) and a core cylindrical wall (in the piston wall), and contemplates that the core may be comprised of one or more core materials (pgh. 0045), such materials are described in pgh. 0035, to “include cast iron, steel, stainless steel, titanium, aluminum, carbon steel, the like, or any combination thereof”. Upon making a core with multiple different materials by selecting a different material for the wall and base, and forming the wall separately from the base, one of ordinary skill in the art arrives at the claimed invention. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided a different material for the wall than the base as suggested by Reuss to fine tune the material properties for each section to optimize strength, weight and cost. For example, it may be desirable for the wall to have a larger compressive strength than the base, as the wall has a smaller surface area to transfer the brake force to the brake pad as compared to the entire back surface of the base exposed to the brake fluid. Accordingly, it may be desirable to construct the metallic portion of the wall out of steel, while the metallic portion of the base is made of aluminum, as this portion requires less compressive strength, but a benefit is achieved of minimizing weight of the piston. When constructing the core material in this manner, one of ordinary skill in the art arrives at the claimed invention.
Regarding claim 13, Rueckert discloses (fig. 4) the metallic portion of the piston base or the metallic portion of the piston wall comprises a sheet metal or a cast metal (“sheet metal strip”).
Regarding claim 14, Rueckert does not appear to disclose the recited materials for at least one of the metallic portions. Reuss teaches a core member having a closed end support portion (in the piston base) and a core cylindrical wall (in the piston wall), and contemplates that the core may be comprised of one or more core materials (pgh. 0045), such materials are described in pgh. 0035, to “include cast iron, steel, stainless steel, titanium, aluminum, carbon steel, the like, or any combination thereof”. Upon selecting steel or aluminum for the wall and base portions, one of ordinary skill in the art arrives at the claimed invention. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have selected the materials of Reuss for the metallic portions of the base or wall to fine tune the material properties for each section to optimize strength, weight and cost. For example, it may be desirable for the wall to be made of steel since it would then have a large compressive strength, as the wall has a small surface area to transfer the brake force to the brake pad. Similarly, it may be desirable to construct the metallic portion of the base is made of aluminum, as this portion requires less compressive strength, but a benefit is achieved of minimizing weight of the piston. When constructing the core material in this manner, one of ordinary skill in the art arrives at the claimed invention.
Regarding claim 15, Rueckert does not appear to disclose a thermoplastic for the plastic portion of the base or wall. In the same field of endeavor of brake pistons, Reuss teaches a brake piston 10 having a wall portion at least made of thermoplastic polymer (pgh. 0035). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized a thermoplastic polymer as the material for the wall as suggested by Reuss to prevent heat transfer to the brake fluid while allowing for ease of manufacturing due to the ability to be injection molded (see pgh. 0035 at least).
Regarding claim 16, Rueckert does not appear to disclose the thickness of the piston base or metallic base portion. Reuss teaches (pgh. 0031) the closed end of the piston (i.e. the piston base) having a thickness of “about 5mm”, which lies within the claimed range of 4-8mm. ). Additionally, Reuss teaches a support portion of the closed end (i.e. metallic base portion) having a thickness of “about 1mm or greater”, which could include 3mm, and “about 5mm”, both of which incorporate the claimed range of 3-5mm. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have made the piston base about 5mm thick to allow for appropriate strength and structural rigidity of the piston, particularly to support the piston walls under axial load while compressing the brake. For example, if the base is too thin, the base could bend axially when pressed by fluid pressure from one side and axial forces from the wall on the perimeter of the base. Alternatively, if the wall is too thick the device becomes unnecessarily heavy. It is additionally noted that such a modification amounts to a mere change in size of a known element, which has been held to involve only routine skill in the art. In re Rose, 105 USPQ 237 (CCPA 1955).
Regarding claim 17, Rueckert discloses a hydraulic brake system 10 for a vehicle (capable of being used for a vehicle, at least), comprising: a housing (where the piston is mounted, not discussed in detail), a brake pad (see claims) and the piston according to claim 1, wherein the piston is movable along a longitudinal axis (vertically in fig. 4) by hydraulic pressure acting on the piston base (see claims), for pressing the second end of the piston against the brake pad (see claims).
Response to Arguments
Applicant’s arguments have been considered but are moot. While the amendments to the claims have alleviated the previous rejection, a new ground of rejection is made as appears above.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DAVID MORRIS whose telephone number is (571)270-3595. The examiner can normally be reached Monday thru Friday; 8:30 AM - 5:00 PM.
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/DAVID MORRIS/
Primary Examiner
Art Unit 3616
/DAVID R MORRIS/Primary Examiner, Art Unit 3616