DETAILED ACTION
Drawings
The drawings were received on 8/31/2026. These drawings are accepted.
Claim Rejections - 35 USC § 102
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 1-14 are rejected under 35 U.S.C. 102(a)(1) as being clearly anticipated by Chung (US Pat. 6,991,572).
Regarding claim 1, Chung discloses a differential lock assembly comprising:
a differential (Fig. 4) comprising a differential cage (22);
a friction pack (e.g., 74, 76); and
a piston bearing actuator system comprising a piston (90), a bearing (112), and an actuator (100,102/104, 80) abutting the friction pack (74, 76), (Figs. 4-7) wherein the piston (90) is an outer race (e.g., both axially and radially from center) for the bearing and the actuator (e.g., portion 110/100) is an inner race for the bearing (Fig. 4), and wherein the differential cage (e.g., supporting portion 54 of cage) is supported by the piston bearing actuator system, (Fig. 4-5) and is configured to rotate independently of a housing (24) of the differential, and wherein the piston directly contacts and defines a volume of a hydraulic actuation chamber (92) and wherein the piston is translatable via hydraulic pressure applied directly against the piston. (Figs. 4-7; C5/L19-32)
Claims 2-14 are clearly anticipated by Chung.
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 1-14 are rejected under 35 U.S.C. 103 as being unpatentable over Mueller (US Pat. 4,644,823) in view of Folino et al. (WO2005/019687)
Regarding claim 1, Mueller discloses a differential lock assembly comprising:
a differential (Fig. 1) comprising a differential cage (3);
a friction pack (14); and
a piston bearing actuator system comprising a piston (18’ and 22; C3/L2-8), a bearing 18, and an actuator (18”/19/20/21/16) abutting the friction pack (14), (Fig. 1) wherein the piston (18’) is an outer race for the bearing (18) and the actuator (18”/19/20/21/16, portion 18” specifically) is an inner race for the bearing (18), and wherein the differential cage (3) is supported by the piston bearing actuator system, (Fig. 1) and is configured to rotate independently of a housing (e.g., 1 and 2) of the differential (Fig. 1, piston bearing actuator system supports cage 3 relative to housing 1 and 2).
Mueller does not explicitly disclose wherein the piston directly contacts and defines a volume of a hydraulic actuation chamber, and wherein the piston is translatable via hydraulic pressure applied directly against the piston.
However, Mueller does disclose that a hydraulic ring (22) abuts against piston (18”), wherein the hydraulic ring contacts and defines a volume of a hydraulic actuation chamber and is translatable via hydraulic pressure applied directly against the hydraulic ring applied with hydraulic pressure to then translate the piston through the abutting relationship (Fig. 1; C3/L2-13). In other words, Mueller discloses the piston is indirectly actuated by the hydraulic pressure rather than directly.
Folino teaches a similar differential lock assembly including a differential (Fig. 1), a friction clutch member (Fig. 1; [0024]) and piston bearing actuator system including a piston (202/206), a bearing(204) and an actuator (21/24) abutting the friction clutch member, (Fig. 1) wherein the piston and actuator serve as respective bearing races for the bearing (204), and further wherein the piston is directly actuated via an actuator (203 e.g., “hydraulic actuation system”) such that the piston is translatable via hydraulic pressure applied directly against the piston. (Fig. 1; [0023], [0035])
In view of Mueller’s disclosure and Folino’s teaching, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Mueller’s disclosed hydraulic ring and piston to be formed into one integral piece (i.e., a piston), as taught by Folino such that the piston directly contacts and defines a volume of a hydraulic actuation chamber (instead of the hydraulic ring alone) and wherein the piston is translatable via hydraulic pressure applied directly against the piston for the purpose of reducing the number of parts simplifying the assembly and manufacture and the differential lock system while also reducing costs.
Regarding claim 2, Mueller as modified above discloses wherein the actuator and the differential cage spin at a first rotational speed and the piston spins at a second rotational speed different from the first rotational speed. (Fig. 1; fully capable via bearing 18 enabling relative rotation between races)
Regarding claim 3, Mueller as modified above discloses wherein there is a plurality of bearings (18) between the actuator (18”/19/20/21/16) and the piston (18’). (Fig. 1)
Regarding claim 4, Mueller as modified above discloses wherein the bearings (18) are ball bearings. (Fig. 1)
Regarding claim 5, Mueller as modified above discloses wherein the differential cage (3) for the differential comprises a drum (left side of figure 1) and a plurality of locking features (15) of the friction pack (14) are rigidly coupled to the drum (C2/L60-62; “outer lamellae 15 are non-rotatably held in axial grooves of the differential housing 3”, col. 2, lines 60-62) and wherein the differential cage (3) is further supported by a first bearing assembly (e.g., tapered roller bearing beneath reference numeral 13 in housing portion 1) and a second bearing assembly (e.g., tapered roller bearing to the left of lip seal 8 in housing portion 2) configured to allow the differential cage to rotate independently of the housing of the differential (e.g., 1 and/or 2) and a plurality of housings (e.g., 5 and 6) of an axle assembly. (Fig. 1)
Regarding claim 6, Mueller as modified above discloses a side gear (9) for the differential is rigidly coupled to a hub (i.e., axially extending to the left in figure 1), and a plurality of disks (13) of the friction pack (14) are rigidly coupled to the hub (C2/L56-60), wherein the friction pack (14) is a disk pack (“lamellae package”) and selectively couples the side gear (9) to a differential housing (3).
Regarding claim 7, Mueller as modified above discloses wherein the side gear (9) comprises the hub. (Fig. 1; C2/L56-57)
Regarding claim 8, Mueller as modified above discloses wherein the piston (18’) is hollow with an opening that surrounds the actuator (particularly portion 8”). (Fig. 1)
Regarding claim 9, Mueller as modified above discloses wherein the actuator (18”/19/20/21/16) is hollow, and a shaft (6) extends through a volume (e.g., of portion 18”) of the actuator. (Fig. 1)
Regarding claim 10, Mueller as modified above discloses wherein the volume of the actuator (e.g., portion 18”) has a constant diameter.
Regarding claim 11, Mueller as modified above discloses wherein the piston (18’) comprises a land, the land extending in an axial direction (i.e., extending toward the right in figure 1 to hydraulic ring 22) from a surface of the piston (18’). (Fig. 1)
Regarding claim 12, Mueller as modified above discloses wherein the actuator (18”/19/20/21/16) includes a land (20) extending radially outward from the actuator. (Fig. 1)
Regarding claim 13, Mueller as modified above discloses wherein a first surface (e.g., extending from the point 26 radially outward) and a second surface (e.g., around the outer circumference of 20) are contiguous, the first surface and second surface are outer surfaces, (Fig. 1) the first surface curves radially outward toward the second surface, the second surface curving radially around the land (20). (Fig. 1)
Regarding claim 14, Mueller as modified above discloses wherein the friction pack (14) is arranged between a differential housing (3; left side) for the differential and the piston (18’).
Allowable Subject Matter
Claims 15 and 18-20 are allowed.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-14 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
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/ERNESTO A SUAREZ/Supervisory Patent Examiner, Art Unit 3655
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