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 .
Status of Claims
This is the first office action on the merits of Application No. 19/160,738 filed on 08/28/2025. Claims 1-3, 5-13, 15-18, 20-23 are pending. Claims 1, 10, and 16 are independent claims. Claims 4, 14, and 19 are cancelled.
Claim Objections
Claims 1, 10-13, 15-16, and 21 are objected to because of the following informalities:
Claim 1, the claim limitation “the vehicle differential system “ should read “the vehicle differential arrangement” since the preamble recites a differential arrangement.
Similar issue has been observed in claims 10 and 16 and should be corrected accordingly.
Claims 11-13 and 15 recites the preamble “The vehicle differential system of claim” should read “The vehicle differential arrangement of claim”.
Claim 21 recites the limitation “the gear casing radial flange” and “the main casing radial extension“ should read “the radial flange” and “the radial extension”.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3, 5-6, 10-13, 15-16, and 20-23 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Hirota et al. (US 20220213952 A1).
Regarding claim 1, Hirota discloses a differential arrangement (e.g. 1, fig. 1 or 101, fig. 8) of a vehicle drive system, the differential arrangement being operationally disposed between a drive gear (not shown, a transmission gear, see para 33) driven by a drive shaft (not shown, see para 33), a first output shaft (not shown, the shaft connect to coupling 49, see para 40) to a first wheel (not shown, see para 47), and a second output shaft (not shown, the shaft connect to coupling 51, see para 40) to a second wheel, the vehicle differential system (101) comprising:
a differential casing (3, para 19) extending along an axis between opposite first and second ends, the differential casing defining a first axial passage (e.g. at 45) extending to the first end and a second axial passage (e.g. at 43) extending to the second end, the differential casing (3) including:
a main casing (21) having a first main body defining the first axial passage leading to an interior of the main casing (21), the main casing including a radial extension (39) extending radially outwardly from the first main body;
a gear casing (25) configured to mount to the main casing (21) to enclose the interior of the main casing, the gear casing having a second main body defining the second axial passage therethrough, the gear casing also including a radial flange (37) extending outwardly from the second main body to an outer ring (23) that defines external gear teeth (27), the outer ring and the gear teeth being monolithically formed (see para 21) with the radial flange.
Regarding claim 2, Hirota discloses the differential arrangement (e.g. 101, fig. 8) of claim 1, wherein the radial flange (37) of the gear casing (25) abuts the radial extension of the main casing (21) when the gear casing (25) is mounted to the main casing (21).
Regarding claim 3, Hirota discloses the differential arrangement (e.g. 101, fig. 8) of claim 2, wherein the radial flange (37) and the radial extension (39) each define fastener (e.g. 47) openings that align with each other when the gear casing (25) is mounted to the main casing (21), and wherein a plurality of bolts (e.g. 47, see para 32) extend through the fastener openings to secure the gear casing (25) to the main casing (21).
Regarding claim 5, Hirota discloses the differential arrangement (e.g. 101, fig. 8) of claim 1, wherein the main casing (21) extends along the axis between respective first and second axial ends, the radial extension (39) being disposed at the first axial end; and wherein the gear casing (25) extends along the axis between respective first and second axial ends, the radial flange (37) being recessed axially inwardly from the second axial end.
Regarding claim 6, Hirota discloses the differential arrangement (e.g. 101, fig. 8) of claim 1, wherein the outer ring (23) extends axially beyond the radial flange (37) of the gear casing (25) towards the first end of the differential casing.
Regarding claim 10, Hirota discloses a differential arrangement (e.g. 1, fig. 1 or 101, fig. 8) of a vehicle drive system, the differential arrangement being operationally disposed between a drive gear (not shown, a transmission gear, see para 33) driven by a drive shaft (not shown, see para 33), a first output shaft (not shown, the shaft connect to coupling 49, see para 40) to a first wheel (not shown, see para 47), and a second output shaft (not shown, the shaft connect to coupling 51, see para 40) to a second wheel, the vehicle differential system (101) comprising:
a differential casing (3, 25, 21, para 19) defining an interior, a first shaft passage (e.g. at 45) leading to the interior from a first end of the differential casing (3, fig. 8), and a second shaft passage (e.g. at 43) leading to the interior form a second end of the differentia casing (3), the first shaft passage being configured to receive the first output shaft, and the second shaft passage being configured to receive the second output shaft;
a torque transfer arrangement (e.g. 5, 41, 49, 51) disposed within the interior of the differential casing (3), the torque transfer arrangement including a plurality of gears (5, 49, 51) configured to transfer a rotation of the differential casing (3) to rotation of the first and second output shafts;
a ring gear (27) monolithically formed with the differential casing (e.g. 25), the ring gear including gear teeth (27) at an outer periphery of the ring gear, the gear teeth being configured to engage with the drive gear (see para 33) to rotate the differential casing (3); and
a radial flange (37) formed with the differential casing (25) and extending to the ring gear (27), wherein the radial flange is recessed inwardly from axial ends of the ring gear.
Regarding claim 11, Hirota discloses the vehicle differential system of claim 10, wherein the differential casing (3) includes a first housing piece (25) and a second housing piece (21), the ring gear being monolithically formed with the first housing piece, the second housing piece holding the torque transfer arrangement.
Regarding claim 12, Hirota discloses the vehicle differential system of claim 11, wherein the second housing piece (21) is fastened (via 47) to the first housing piece (25).
Regarding claim 13, Hirota discloses the vehicle differential system of claim 11, wherein the first housing piece (25) includes the radial flange (37) and an annular flange (23) extending around a periphery of the radial flange, the annular flange forming the ring gear.
Regarding claim 15, Hirota discloses the vehicle differential system of claim 13, wherein the ring gear (27) extends axially over the radial flange (37) of the first housing piece (25) and axially over a radial extension (39) of the second housing piece (21).
Regarding claim 16, Hirota discloses a differential arrangement (e.g. 1, fig. 1 or 101, fig. 8) of a vehicle drive system, the differential arrangement being operationally disposed between a drive gear (not shown, a transmission gear, see para 33) driven by a drive shaft (not shown, see para 33), a first output shaft (not shown, the shaft connect to coupling 49, see para 40) to a first wheel (not shown, see para 47), and a second output shaft (not shown, the shaft connect to coupling 51, see para 40) to a second wheel, the vehicle differential system (101) comprising:
a differential casing (3, 25, 21, para 19) defining an interior, a first shaft passage (e.g. at 45) leading to the interior from a first end of the differential casing (3, fig. 8), and a second shaft passage (e.g. at 43) leading to the interior form a second end of the differentia casing (3), the first shaft passage being configured to receive the first output shaft, and the second shaft passage being configured to receive the second output shaft;
the differential casing (25) including a ring gear (27) monolithically formed with the first shaft passage, the ring gear including gear teeth (27) at an outer periphery of the differential casing (25),
a torque transfer arrangement (e.g. 5, 41, 49, 51) disposed within the interior of the differential casing (3).
Regarding claim 20, Hirota discloses the vehicle differential arrangement of claim 16, wherein the differential casing (3) includes a first housing piece (25) and a second housing piece (21), the ring gear being monolithically formed with the first housing piece, the second housing piece holding the torque transfer arrangement.
Regarding claim 21, Hirota discloses the vehicle differential arrangement of claim 1, wherein the outer ring (27) extends axially (23) over first and second sides of the gear casing radial flange (37) and axially over the main casing radial extension.
Regarding claim 22, Hirota discloses the vehicle differential arrangement of claim 1, further comprising a plurality of bolts (e.g. 47, para 32) securing the radial extension (37) to the radial flange (39) and wherein the outer ring (27) extends axially (23) over first and second sides of the radial flange and axially over the plurality of bolts on a side opposite the main casing.
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.
Claims 7-9, and 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Hirota et al. (US 20220213952 A1) in view of Zhang (US 20200147724 A1).
Regarding claims 7-8, Hirota discloses all the elements of the differential arrangement (e.g. 101, fig. 8) of claim 1, but fails to disclose wherein the main casing is formed of a different material from the gear casing and wherein the main casing is formed cast iron and the gear casing is formed of steel.
Zhang teaches a similar kind of differential arrangement (e.g. 110, fig. 6) wherein the main casing (12, fig. 1) is formed of a different material from the gear casing (14) and wherein the main casing is formed cast iron and the gear casing is formed of steel. (see para 16)
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Hirota by substituting the material of the main casing and gear casing as taught by Zhang, such as the cast iron and steel exhibit enhanced torsional strength, good impact and fatigue resistance, and good wear resistance. (see paras 19 and 21)
Regarding claim 9, Hirota discloses all the elements of the differential arrangement (e.g. 101, fig. 8) of claim 1, but fails to disclose wherein the gear teeth of the outer ring form a helical gear.
Zhang teaches a similar kind of differential arrangement (e.g. 110, fig. 6) wherein the gear teeth (62) of the outer ring form (14) a helical gear. (see para 20 “The gear teeth 62 may be curved (as shown) or straight.”)
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Hirota by substituting the straight teeth with the helical one as taught by Zhang, such as the helical tooth profile improves smoothness and load distribution, particularly in high-speed or high-torque transmission.
Regarding claims 17-18, Hirota discloses all the elements of the differential arrangement (e.g. 101, fig. 8) of claim 16, but fails to disclose wherein the main casing is formed of a different material from the gear casing and wherein the main casing is formed cast iron and the gear casing is formed of steel.
Zhang teaches a similar kind of differential arrangement (e.g. 110, fig. 6) wherein the main casing (12, fig. 1) is formed of a different material from the gear casing (14) and wherein the main casing is formed cast iron and the gear casing is formed of steel. (see para 16)
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Hirota by substituting the material of the main casing and gear casing as taught by Zhang, such as the cast iron and steel exhibit enhanced torsional strength, good impact and fatigue resistance, and good wear resistance. (see paras 19 and 21)
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Hirota et al. (US 20220213952 A1) in view of JANSON et al. (US 9914357 B1).
Regarding claim 23, Hirota discloses the vehicle differential arrangement of claim 1, wherein the radial flange (37) defines a first axial thickness and the outer ring (27) defines a second axial thickness but fails to disclose the second axial thickness is at least twice as large as the first axial thickness.
JANSON teaches a similar kind of differential arrangement (e.g. 16, fig. 2) wherein the radial flange (90) defines a first axial thickness and the outer ring (94) defines a second axial thickness that is at least twice as large as the first axial thickness.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Hirota by substituting the thickness of outer ring as taught by JANSON, such as the ring gear can transfer torque smoothly and reliably.
Prior Art
The prior art made of record and not relied upon is considered pertinent to Applicant's disclosure.
MUMMIGATTI et al. (US 20170067550 A1) teaches a differential arrangement (20, figs. 1-2) of a vehicle drive system (e.g. 10, fig. 1), the differential arrangement being operationally disposed between a drive gear (22, fig. 1) driven by a drive shaft (18, fig. 1), a first output shaft (76R) to a first wheel (not shown, see para 3), and a second output shaft (76L, see para 3) to a second wheel, the vehicle differential system (20) comprising:
a differential casing (e.g. 30, 50, fig. 2) extending along an axis between opposite first and second ends, the differential casing defining a first axial passage (e.g. at 56, para 29) extending to the first end and a second axial passage (e.g. at 38, para 27) extending to the second end, the differential casing (50) including:
a main casing (50) having a first main body defining the first axial passage leading to an interior of the main casing (50), the main casing including a radial extension (52, para 28) extending radially outwardly from the first main body;
a gear casing (30) configured to mount to the main casing (50) to enclose the interior of the main casing, the gear casing having a second main body defining the second axial passage therethrough, the gear casing also including a radial flange (32, para 27) extending outwardly from the second main body to an outer ring (24, para 26) that defines external gear teeth (26).
Sudorowski et al. (US 7591751 B2) discloses a differential having four pinions supported for rotation on cross pins within a differential case. The differential employs a retainer system for securing the cross pins relative to the differential case. The retainer system can include a retainer, such as a clip or a pair of roll pins, that can secure at least one of the cross pins in place.
Conclusion
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/F.P/Examiner, Art Unit 3655
/FARHANA PERVIN/Examiner, Art Unit 3655
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