Prosecution Insights
Last updated: July 17, 2026
Application No. 18/675,773

AUXILIARY POWER UNIT AIR CONDITIONING FOR TRUCK CAB COOLING

Final Rejection §103§112
Filed
May 28, 2024
Priority
May 29, 2019 — provisional 62/854,043 +1 more
Examiner
BARNETT, JOEL
Art Unit
2849
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Illinois Tool Works Inc.
OA Round
2 (Final)
81%
Grant Probability
Favorable
3-4
OA Rounds
7m
Est. Remaining
93%
With Interview

Examiner Intelligence

Grants 81% — above average
81%
Career Allowance Rate
358 granted / 443 resolved
+12.8% vs TC avg
Moderate +12% lift
Without
With
+11.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
30 currently pending
Career history
476
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
81.2%
+41.2% vs TC avg
§102
5.1%
-34.9% vs TC avg
§112
4.4%
-35.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 443 resolved cases

Office Action

§103 §112
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 . Response to Arguments/Amendments Applicant’s amendment filed 2 March 2026 with respect to the claim objection of claim 5 and the 35 USC § 112 rejection of claim 9 correct the issues and these are therefore withdrawn. However, the 35 USC § 112 rejection of claim 6 was not addressed and is maintained. Applicant’s arguments, filed 2 March 2026, with respect to 35 USC § 112 rejection of claims 4-5 have been fully considered and are persuasive. The 35 USC § 112 rejection of claims 4-5 has been withdrawn. Applicant's arguments filed 2 March 2026 with respect to “a controller configured to activate the auxiliary compressor to pump fluid through the coolant loop in response to determining that a temperature within a volume of the vehicle is greater than a set point temperature” have been fully considered but they are not persuasive. Please see below. Applicant’s arguments with respect to “wherein the auxiliary engine is configured to provide power to one or more additional loads” is a newly added amendment that is addressed below. 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. Claim 6 is 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 applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 6 recites the limitation "the auxiliary generator" in line 4. There is insufficient antecedent basis for this limitation in the claim. Claim Rejections - 35 USC § 103 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 1-12 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0324616 (previously published as WO2019/102451) by Farhi et al. (Farhi hereinafter) in view of US 9,211,881 by Waldschmidt et al. (Waldschmidt hereinafter). Regarding claim 1, Farhi discloses an auxiliary compressor system [see at least Figure 1] comprising: an auxiliary compressor [see at least Figure 1, (150)] selectively driven by an auxiliary engine [see at least Figure 1, (152)]; and one or more conduits connected to the auxiliary compressor [see at least Figure 1, (154b) and (156b)], the auxiliary compressor to selectively [see at least Figure 1, (140a) and (140b); paragraphs 0020-022] pump fluid through a coolant loop [see at least Figure 1, (30) to (80)] of a cooling system [see at least Figure 1, (30)] integrated within a vehicle [see at least abstract] via the one or more conduits [see at least Figure 1, (154b) and (156b)], wherein the cooling system is connected to a vehicle compressor [see at least Figure 1, (50)] driven by a vehicle engine [see at least Figure 1, (20)]; and a controller [see at least Figure 1, (110)] configured to activate the auxiliary compressor to pump fluid through the coolant loop in response to determining that a temperature within a volume of the vehicle is greater than a set point temperature [see at least paragraph 0021, “Upon determining that the ambient temperature inside the cabin is above a preconfigured threshold temperature, the auxiliary controller (110) is configured to activate the auxiliary electric alternator-motor, the blower, the fan, the electric relay switches and the auxiliary compressor”]. Farhi fails to disclose wherein the auxiliary engine is configured to provide power to one or more additional loads; and determining that a total power demand on the auxiliary engine from the one or more additional loads is less than a threshold. However, Waldschmidt discloses control of an auxiliary power unit (APU) of a vehicle [see at least Abstract] which power multiple loads [see at least column 6, line 45 – column 7, line 40, “compressor load” and “alternator load”] while operating the APU below its total power output [see at least column 6, line 45 – column 7, line 40, “operates the auxiliary power unit 55 continuously from time T.sub.0 to time T.sub.3 without exceeding the total power output of the auxiliary engine 85”] in order to accommodate the compressor load [see at least column 6, line 45 – column 7, line 40, “The alternator load can be applied and removed relative to the auxiliary engine 85 anytime while the auxiliary engine 85 is running to accommodate the compressor load being applied to the auxiliary engine 85 when the compressor 75 changes from the off state to the on state. In some constructions, the control system 105 applies and removes the auxiliary alternator load relative to the auxiliary engine 85 in view of the state of the compressor 75 and also in view of the state of charge of the electrical storage system 100”]. It would have been obvious to a person of ordinary skill in the art before the effective filing of the Applicant's invention to modify the cooling system of Farhi to include the multiple loads and load management of the auxiliary power unit, as disclosed by Waldschmidt, in order to keep the APU load below its maximum output while providing power to other loads. Thus, ensuring that the cooling system remains operational. Regarding claim 2, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 1. Farhi discloses further comprising one or more valves [see at least Figure 1, (140a) and (140b)] configured to selectively channel fluid from one of the auxiliary compressor or the vehicle compressor through the coolant loop [see at least paragraphs 0020-0022]. Regarding claim 3, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 1. Farhi discloses wherein the controller [see at least Figure 1, (110)] is configured to: receive control signals to activate the cooling system [see at least Figure 3, (310)]; and control the auxiliary engine or the auxiliary compressor based on the control signals [see at least Figure 3]. Regarding claim 4, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 3. Farhi discloses wherein the cooling system comprises a cooling control system [see at least Figure 1, (110)] operable to receive inputs from one or more sensors [see at least Figure 1, (120)], a user interface, or a vehicle control system. Regarding claim 5, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 4. Farhi discloses wherein the cooling system comprises a cooling control system to generate the control signals based on the received inputs [see at least Figure 3, (310)]. Regarding claim 6, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 3. Farhi discloses wherein the controller further comprises a memory storage device [the definition of a controller includes memory and a processor] that includes a list of threshold power characteristic values [see at least Figure 5, (515), (525) and (555)] corresponding to a power allocation scheme [see at least Figure 5] for one or more auxiliary devices including the auxiliary compressor, the auxiliary generator, a battery charger [see at least Figure 5, (510)], or a welding-type power output. Regarding claim 7, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 6. Farhi discloses wherein the controller is further configured to: receive power characteristics corresponding to the one or more auxiliary devices [see at least Figure 5, (510)]; compare the received power characteristics to the list of threshold power characteristics [see at least Figure 5, (515) and (525)]; and adjust power output to one or more of the one or more auxiliary devices based on the comparison [see at least Figure 5, (530)]. Regarding claim 8, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 3. Farhi discloses wherein the controller is operable to increase a speed of the auxiliary engine to drive the auxiliary compressor in response to the control signals [see at least Figure 3, (360); the motor is activated from off and no speed, to on with speed]. Regarding claim 9, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 3. Farhi discloses wherein the controller is operable to control the clutch to activate to drive the auxiliary compressor in response to the control signals [see at least paragraphs 0025 and 0125]. Regarding claim 10, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 3. Farhi discloses wherein the controller is further configured to: receive control signals to deactivate the cooling system [see at least Figure 3, (380)-(384)]; receive data that the vehicle compressor is not being driven by the vehicle engine [see at least Figure 3, (385) or (301)]; and control the engine to drive the auxiliary compressor based on the control signals [see at least Figure 3, (320)-(360)]. Regarding claim 11, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 1. Farhi discloses wherein the controller is further operable to receive vehicle engine state information from a vehicle control system [see at least Figure 3, (385) or (301)]. Regarding claim 12, Farhi in view of Waldschmidt teaches the auxiliary compressor system as defined in claim 3. Farhi discloses wherein the controller is further operable to transmit or receive information to or from the vehicle control system via a wired or a wireless communications interface [see at least Figure 1, dash lines to controller (110)]. Regarding claim 20, Farhi discloses an auxiliary compressor system [see at least Figure 1] comprising: an auxiliary compressor [see at least Figure 1, (150)] selectively driven by an auxiliary engine [see at least Figure 1, (152)]; one or more conduits connected to the auxiliary compressor [see at least Figure 1, (154b) and (156b)], the auxiliary compressor to selectively pump fluid [see at least paragraphs 0020-0022] through a coolant loop [see at least Figure 1, (30) to (80)] of a cooling system [see at least Figure 1, (30)] via the one or more conduits [see at least Figure 1, (154b) and (156b)], wherein the cooling system is connected to a primary compressor [see at least Figure 1, (50)] driven by a primary engine [see at least Figure 1, (20)]; and a controller [see at least Figure 1, (110)] to: receive a temperature signal representative of a temperature within a volume of he truck [see at least Figure 3, (310); paragraph 0021, “Upon determining that the ambient temperature inside the cabin is above a preconfigured threshold temperature, the auxiliary controller (110) is configured to activate the auxiliary electric alternator-motor, the blower, the fan, the electric relay switches and the auxiliary compressor”]; receive control signals to activate the auxiliary compressor [see at least Figure 3, (315)]; and control the auxiliary engine to drive the auxiliary compressor based on the temperature signal [see at least Figure 3, (320)-(360); paragraph 0021, “Upon determining that the ambient temperature inside the cabin is above a preconfigured threshold temperature, the auxiliary controller (110) is configured to activate the auxiliary electric alternator-motor, the blower, the fan, the electric relay switches and the auxiliary compressor”]. Farhi fails to disclose wherein the auxiliary engine is configured to provide power to one or more additional loads; and determining that a total power demand on the auxiliary engine from the one or more additional loads is less than a threshold. However, Waldschmidt discloses control of an auxiliary power unit (APU) of a vehicle [see at least Abstract] which power multiple loads [see at least column 6, line 45 – column 7, line 40, “compressor load” and “alternator load”] while operating the APU below its total power output [see at least column 6, line 45 – column 7, line 40, “operates the auxiliary power unit 55 continuously from time T.sub.0 to time T.sub.3 without exceeding the total power output of the auxiliary engine 85”] in order to accommodate the compressor load [see at least column 6, line 45 – column 7, line 40, “The alternator load can be applied and removed relative to the auxiliary engine 85 anytime while the auxiliary engine 85 is running to accommodate the compressor load being applied to the auxiliary engine 85 when the compressor 75 changes from the off state to the on state. In some constructions, the control system 105 applies and removes the auxiliary alternator load relative to the auxiliary engine 85 in view of the state of the compressor 75 and also in view of the state of charge of the electrical storage system 100”]. It would have been obvious to a person of ordinary skill in the art before the effective filing of the Applicant's invention to modify the cooling system of Farhi to include the multiple loads and load management of the auxiliary power unit, as disclosed by Waldschmidt, in order to keep the APU load below its maximum output while providing power to other loads. Thus, ensuring that the cooling system remains operational. Claims 13-19 are rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0324616 (previously published as WO2019/102451) by Farhi et al. (Farhi hereinafter) in view of US 9,211,881 by Waldschmidt et al. (Waldschmidt hereinafter) and US 2012/0085830 by Sundhar. Regarding claim 13, Farhi discloses a power system comprising: cooling system is connected to a vehicle compressor [see at least Figure 1, (50)] driven by a vehicle engine [see at least Figure 1, (20)]; and a controller [see at least Figure 1, (110)] configured to activate the auxiliary compressor to pump fluid through the coolant loop in response to determining that a temperature within a volume of the vehicle is greater than a set point temperature [see at least paragraph 0021, “Upon determining that the ambient temperature inside the cabin is above a preconfigured threshold temperature, the auxiliary controller (110) is configured to activate the auxiliary electric alternator-motor, the blower, the fan, the electric relay switches and the auxiliary compressor”]. Farhi fails to disclose wherein the auxiliary engine is configured to provide power to one or more additional loads; and determining that a total power demand on the auxiliary engine from the one or more additional loads is less than a threshold. However, Waldschmidt discloses control of an auxiliary power unit (APU) of a vehicle [see at least Abstract] which power multiple loads [see at least column 6, line 45 – column 7, line 40, “compressor load” and “alternator load”] while operating the APU below its total power output [see at least column 6, line 45 – column 7, line 40, “operates the auxiliary power unit 55 continuously from time T.sub.0 to time T.sub.3 without exceeding the total power output of the auxiliary engine 85”] in order to accommodate the compressor load [see at least column 6, line 45 – column 7, line 40, “The alternator load can be applied and removed relative to the auxiliary engine 85 anytime while the auxiliary engine 85 is running to accommodate the compressor load being applied to the auxiliary engine 85 when the compressor 75 changes from the off state to the on state. In some constructions, the control system 105 applies and removes the auxiliary alternator load relative to the auxiliary engine 85 in view of the state of the compressor 75 and also in view of the state of charge of the electrical storage system 100”]. It would have been obvious to a person of ordinary skill in the art before the effective filing of the Applicant's invention to modify the cooling system of Farhi to include the multiple loads and load management of the auxiliary power unit, as disclosed by Waldschmidt, in order to keep the APU load below its maximum output while providing power to other loads. Thus, ensuring that the cooling system remains operational. Farhi in view of Waldschmidt fails to specifically teach an enclosure (although it is fully believed that all components are within an engine compartment). However, Sundhar discloses this limitation [see at least Figure 1A; paragraph 0011]. It would have been obvious to a person of ordinary skill in the art before the effective filing date of the Applicant's invention to enclose the components of the power system to protect these components from environmental elements, thus increasing the longevity and reliability of the components. Regarding claim 14, Farhi in view of Waldschmidt and Sundhar teaches the power system as defined in claim 13. Farhi discloses wherein the one or more conduits connect to the coolant loop via one or more valves [see at least Figure 1, (140a) and (140b)]. Regarding claim 15, Farhi in view of Waldschmidt and Sundhar teaches the power system as defined in claim 14. Farhi discloses wherein the one or more valves comprise a connector to secure or remove the one or conduits to the coolant loop [see at least paragraph 0020]. Regarding claim 16, Farhi in view of Waldschmidt and Sundhar teaches the power system as defined in claim 13. Sundhar discloses further comprising a belt to operatively link the clutch to a shaft of the auxiliary compressor [see at least paragraph 0018]. Regarding claim 17, Farhi in view of Waldschmidt and Sundhar teaches the power system as defined in claim 13. Farhi discloses further comprising an energy storage device [see at least Figure 1, (40)] to provide mechanical power to drive the auxiliary compressor [see at least paragraph 0116]. Regarding claim 18, Farhi in view of Waldschmidt and Sundhar teaches the power system as defined in claim 13. Farhi discloses wherein the controller [see at least Figure 1, (110)] is configured to control the auxiliary engine or the auxiliary compressor when the vehicle compressor is not being driven by the vehicle engine [see at least Figure 3]. Regarding claim 19, Farhi in view of Waldschmidt and Sundhar teaches the power system as defined in claim 13. Farhi discloses wherein the controller is further configured to: receive control signals to activate the cooling system [see at least Figure 3, (310)]; receive data that the vehicle compressor is not being driven by the vehicle engine [see at least Figure 3, (385) and (301)]; and control the auxiliary engine to drive the auxiliary compressor based on the control signals and the data [see at least Figure 3, (320)-(360)]. Conclusion THIS ACTION IS MADE FINAL. 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Joel Barnett whose telephone number is (571)272-2879. The examiner can normally be reached Monday - Friday, 9:00 AM - 5:00 PM EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Regis Betsch can be reached at 571-270-7101. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /JOEL BARNETT/Examiner, Art Unit 2836 /REGIS J BETSCH/SPE, Art Unit 2836
Read full office action

Prosecution Timeline

May 28, 2024
Application Filed
Aug 28, 2025
Non-Final Rejection mailed — §103, §112
Mar 02, 2026
Response Filed
May 28, 2026
Final Rejection mailed — §103, §112 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12676485
CONTROLLER, NON-TRANSITORY COMPUTER-READABLE MEDIUM, AND CONTROL METHOD
1y 8m to grant Granted Jul 07, 2026
Patent 12673580
BATTERY CIRCUIT AND VEHICLE
1y 8m to grant Granted Jul 07, 2026
Patent 12671338
Power Conversion System
1y 11m to grant Granted Jun 30, 2026
Patent 12665422
DUAL MODE POWER TRANSFER SWITCHES
2y 2m to grant Granted Jun 23, 2026
Patent 12633781
ARTIFICIAL INTELLIGENCE ALGORITHM-BASED WIRELESS CHARGING SYSTEM CAPABLE OF HIGH-SPEED RESPONSE TO ENVIRONMENTAL CHANGES
1y 6m to grant Granted May 19, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

Strategy Recommendation AI-generated — please review before filing

Get a prosecution strategy drawn from examiner precedents, rejection analysis, and claim mapping.
Typically takes 5-10 seconds — AI-generated, attorney review required before filing

Prosecution Projections

3-4
Expected OA Rounds
81%
Grant Probability
93%
With Interview (+11.9%)
2y 8m (~7m remaining)
Median Time to Grant
Moderate
PTA Risk
Based on 443 resolved cases by this examiner. Grant probability derived from career allowance rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month