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 .
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, 2, 4, 6-8, 10-13, 15, 16, 18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Baar US 20210179212 A1 in view of Вторкин Евгений Юрьевич RU 183776 U1 (hereinafter referred to as the Russian reference)
Regarding claim 1, Baar teaches a track chain assembly comprising: a first link 40 and a second link 42; and a track pin 34 joining the first link 40 to the second link 42, the track pin 34 having a unitary construction (solid pin body; para. 14) and wherein the track pin 34 excludes an interface with a bushing. (Baar uses the term “rotational bushing” to describe the elements that allow rotation between the track pin and the outer track links, the “sealed composite bearing” described by the instant application is generally a solid plain bearing. Bushings are typically a type of plain bearing used for sliding components so the “rotational bushing” described by Baar should more accurately be referred to as a plain bearing as it serves the same function as (and could potentially be) a sealed composite bearing. Because the “rotational bushing” taught by Baar is essentially the same as (and could consist of) the sealed composite bearing in the instant application, the track pin taught by Baar is seen as excluding an interface with a bushing as much as the invention of the instant application does).
Baar does not teach, but the Russian reference teaches, a track pin comprising: a first layer having a thickness up to 10 mm, the first layer having a first hardness within an HRC range from 50 HRC to 70 HRC and a second layer having a second hardness that is less than the first hardness. (Fig. 4; para. 19 of the English language translation) It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use the hardening method taught by the Russian reference to improve the durability and longevity of the track pin with a reasonable expectation of success.
Regarding claim 2, Baar and the Russian reference teach the track chain assembly of claim 1. The Russian reference further teaches wherein the second hardness is within an HRC range from 25 HRC to 35 HRC (Fig. 4). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have the second layer softer to improve ductility and make the pin less likely to break under load with a reasonable expectation of success.
Regarding claim 3 Baar and the Russian reference teach the track chain assembly of claim 1. The Russian reference further teaches wherein the first layer has a substantially martensitic crystal structure (para. 19 of the English language translation).
Regarding claim 6, Baar and the Russian reference teach the track chain assembly of claim 1. The Russian reference further teaches a track pin further comprising a third layer disposed between the first layer and the second layer, the third layer having a hardness between the hardness of the first layer and the hardness of the second layer (Fig. 4; para. 21 of the English language translation). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that a third “transition” layer would help to act as a barrier between the hard outer layer and the soft inner core with a reasonable expectation of success.
Regarding claim 7, Baar and the Russian reference teach the track chain assembly of claim 1. Baar further teaches wherein the track pin 34 further comprises a first bearing 94 (rotatable bushings are a type of bearing; see claim 1) at a first distal end of the track pin and a second bearing 95 at a second distal end of the track pin, wherein the first bearing 94 and the second bearing 95 are sealed composite bearings. (Fig. 2; see claim 1 for explanation of how a sealed composite bearing is essentially a “rotational/rotatable bushing”)
Regarding claim 8, Baar teaches a method for producing a track pin, the method comprising: forming the track pin 34 having a unitary construction, wherein the track pin 34 excludes an interface with a bushing (Fig. 2; see claim 1 for explanation of bushing vs bearing in this instance). Baar does not teach, but the Russian reference teaches using a high carbon steel and differentially hardening the track pin to form: a first layer having a thickness up to 10 mm, the first layer having a first hardness within an HRC range from 50 HRC to 70 HRC; and a second layer having a second hardness less than the first hardness (Fig. 4; para. 21 of the English language translation)
Regarding claim 10 Baar and the Russian reference teach the method of claim 8. The Russian reference further teaches wherein performing the differential hardening comprises: heating the track pin to at least 800 °C for a predetermined period of time; and quenching the track pin (para. 22 of the English language translation). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to harden the track pin in the manner taught by the Russian reference to increase the hardness and improve the grain structure of the track pin with a reasonable expectation of success.
Regarding claim 11 Baar and the Russian reference teach the method of claim 8. The Russian reference further teaches wherein the second layer has a hardness less than 52 HRC (Fig. 4; para. 21 of the English language translation). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to make the second layer softer in order to increase ductility and reduce the chance of fracture under load with a reasonable expectation of success.
Regarding claim 12 Baar and the Russian reference teach the method of claim 8. The Russian reference further teaches wherein the differential hardening further forms a third layer disposed between the first layer and the second layer, the third layer having a hardness between the hardness of the first layer and the hardness of the second layer (Fig. 4; para. 21 of the English language translation). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that a third “transition” layer would help to act as a barrier between the hard outer layer and the soft inner core with a reasonable expectation of success.
Regarding claim 13 Baar and the Russian reference teach the method of claim 8. Baar further teaches installing a first bearing 94 (rotatable bushings are a type of bearing; see claim 1) at a first distal end of the track pin and a second bearing 95 at a second distal end of the track pin, wherein the first bearing 94 and the second bearing 95 are sealed composite bearings. (Fig. 2; see claim 1 for explanation of how a sealed composite bearing is essentially a “rotational/rotatable bushing”)
Regarding claim 15, Baar teaches a track pin having a unitary construction wherein the track pin excludes an interface with a bushing (see claim 1 for the bearing/bushing explanation). Baar does not teach, but the Russian reference teaches a track pin comprising: a first layer having a thickness up to 10 mm, the first layer having a first hardness within an HRC range from 50 HRC to 70 HRC; and a second layer having a second hardness with a second hardness less than the first hardness (Fig. 4; para. 21 of the English language translation). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to differentially harden a track pin in order to reduce wear on the outer surface without fully sacrificing ductility with a reasonable expectation of success.
Regarding claim 16, Baar and the Russian reference teach the track pin of claim 15. The Russian reference further teaches that the second hardness is within an HRC range from 25 HRC to 35 HRC (Fig. 4). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to make the second layer significantly softer than the first layer in order to increase the ductility of the pin with a reasonable expectation of success.
Regarding claim 18, Baar and the Russian reference teach the track pin of claim 15. The Russian reference further teaches that the first layer has a substantially martensitic crystal structure (para. 19 of the English language translation). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the outer surface layer should be substantially martensite in order to increase the durability and wear resistance of the outer surface of the pin with a reasonable expectation of success.
Regarding claim 20, Baar and the Russian reference teach the track pin of claim 15. Baar further teaches a range of a ratio between a center diameter 410 and a distal end diameter 440 is from 1.05 to 1.5 (Fig. 5; para. 22).
Claim(s) 3, 5, 9, 14, 17, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Baar US 20210179212 A1 in view of Вторкин Евгений Юрьевич RU 183776 U1 (hereinafter referred to as the Russian reference) and further in view of Rathod US 20210095355 A1.
Regarding claim 3 Baar and the Russian reference teach the track chain assembly of claim 1. Neither Baar nor the Russian reference teach wherein the second layer has a substantially martensite crystal structure. Rathod teaches a core containing a substantially martensitic crystal structure. It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply the hardness levels and structure taught by the bushing of Rathod to the center section of the pin taught by Baar as they serve the same primary function of engaging the drive teeth of a caterpillar track in order to ensure the track pin would have sufficient durability and lifespan with a reasonable expectation of success.
Regarding claim 5, Baar and the Russian reference teach the track chain assembly of claim 1. Neither Baar nor the Russian reference teach a track pin comprising GB-45B steel, GB-40CR steel, or 52100 steel. Rathod teaches a high-carbon steel such as 52100 should be used to promote sufficient hardenability and wear characteristics (para. 31). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use 52100 steel, which is well known for its high strength and hardenability, to make a track pin out of 52100 to ensure the track pin can be sufficiently hardened to increase wear resistance and lifetime with a reasonable expectation of success.
Regarding claim 9, Baar and the Russian reference teach the method of claim 8. Neither Baar nor the Russian reference teach that the high carbon steel comprises 52100 steel. Rathod teaches a high-carbon steel such as 52100 should be used to promote sufficient hardenability and wear characteristics (para. 31). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use 52100 steel, which is well known for its high strength and hardenability, to make a track pin out of 52100 to ensure the track pin can be sufficiently hardened to increase wear resistance and lifetime with a reasonable expectation of success.
Regarding claim 14 Baar and the Russian reference teach the method of claim 8. Neither Baar nor the Russian reference explicitly teach that forming the track pin comprises forging, shaping, turning, milling, drilling, or grinding the high carbon steel into a desired shape however, all methods are well known in the art so it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use one of the claimed methods to form the track pin with a reasonable expectation of success. Furthermore, Rathod teaches any shaping, turning, milling, drilling, grinding, or other machining techniques may be used (para. 49).
Regarding claim 17 Baar and the Russian reference teach the track pin of claim 15. Neither Baar nor the Russian reference teach wherein the second layer has a substantially martensite crystal structure. Rathod teaches a core containing a substantially martensitic crystal structure. It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply the hardness levels and structure taught by the bushing of Rathod to the center section of the pin taught by Baar as they serve the same primary function of engaging the drive teeth of a caterpillar track in order to ensure the track pin would have sufficient durability and lifespan with a reasonable expectation of success.
Regarding claim 19, Baar and the Russian reference teach the track pin of claim 15. Neither Baar nor the Russian reference teach a track pin comprising GB-45B steel, GB-40CR steel, or 52100 steel. Rathod teaches a high-carbon steel such as 52100 should be used to promote sufficient hardenability and wear characteristics (para. 31). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use 52100 steel, which is well known for its high strength and hardenability, to make a track pin out of 52100 to ensure the track pin can be sufficiently hardened to increase wear resistance and lifetime with a reasonable expectation of success.
Response to Arguments
Applicant's arguments filed 25 August, 2025 have been fully considered but they are not persuasive.
Applicant’s only arguments against the 35 U.S.C §102 and 103 arguments presented in the non-final rejection revolve around the addition of the limitations of “the track pin having a unitary construction” and “the track pin excludes an interface with a bushing” to independent claims 1, 8, and 15. This argument has been addressed in the rejections stated above under 35 U.S.C. §103.
Furthermore, because claims 8-20 relate only to a track pin instead of a track chain assembly, the limitation of “the track pin excludes an interface with a bushing” is a statement of intended use because the bushings that are potentially to be excluded are not part of the track pin structure. A recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. The track pin taught by Baar as modified with the differential hardening taught by the Russian reference and Rathod certainly meets the same structural criteria as the track pin claimed.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/AP/Examiner, Art Unit 3615
/S. Joseph Morano/Supervisory Patent Examiner, Art Unit 3615