Prosecution Insights
Last updated: April 18, 2026
Application No. 16/810,044

CO2 REFRIGERATION SYSTEM

Non-Final OA §112§DP
Filed
Mar 05, 2020
Examiner
ZERPHEY, CHRISTOPHER R
Art Unit
3799
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Toromont Industries Ltd.
OA Round
7 (Non-Final)
48%
Grant Probability
Moderate
7-8
OA Rounds
3y 1m
To Grant
67%
With Interview

Examiner Intelligence

Grants 48% of resolved cases
48%
Career Allow Rate
360 granted / 749 resolved
-21.9% vs TC avg
Strong +19% interview lift
Without
With
+19.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
53 currently pending
Career history
802
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
51.7%
+11.7% vs TC avg
§102
17.9%
-22.1% vs TC avg
§112
23.4%
-16.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 749 resolved cases

Office Action

§112 §DP
Notice of Pre-AIA or AIA Status The present application is being examined under the pre-AIA first to invent provisions. The claims received 11/28/2025 are entered. Claims 7-8 and 16 are cancelled. Claim Interpretation The following is a quotation of 35 U.S.C. 112(f): (f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph: An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked. As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph: (A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function; (B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and (C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function. Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function. Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function. Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. The following limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses means or a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the means or generic placeholder is not preceded by a structural modifier. “a pressure-regulating device” includes the generic/nonce term “device” coupled with the function of “pressure-regulating”. A return to the specification provides a valve or loop ([0051] of the associated PGPub). Therefor the limitation is interpreted as the same or equivalents thereof. Double Patenting A terminal disclaimer was received in view of US 10,690,389 on 2/15/2023 and approved. Priority This application repeats a substantial portion of prior Application No. 14/831,170, filed 8/20/2015, and adds disclosure not presented in the prior application. Because this application names the inventor or at least one joint inventor named in the prior application, it may constitute a continuation-in-part of the prior application. Should applicant desire to claim the benefit of the filing date of the prior application, attention is directed to 35 U.S.C. 120, 37 CFR 1.78, and MPEP § 211 et seq. The new feature is found in claim 1 “for a heat demand of a heat reclaim exchanger in heat exchange relation with a circuit including a heat transfer fluid, causing the pressure of the CO2 refrigerant to reach a transcritical level as a function of said heat demand to absorb heat from the CO2 refrigerant in the gas cooling stage.” Claim quotation is from the original claim set dated 3/05/2020. 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 1-6, 9-15, and 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 applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 1 recites “a cold climate winter condition heat demand”. The phrase is not found within the original disclosure. Claim 16, now cancelled, used the phrase “heat demand during a winter month period”. The phrase of claim 1 is unclear. There are no clear metes and bounds for a cold climate. For example what climate zones are included, such as north American zones, 4, 5, 6, 7, 8, others? Tundra, polar, alpine, etc. It is unclear if the limitation is directed to a geographical region. It is unclear if a winter condition is directed to a portion of the calendar year or an environmental condition. The phrase “the amount of the excess heat away from the at least one coil” is unclear. “the excess heat” has no antecedent basis. The term “away” has unclear meaning as it is used in the phrase. Claim 1 recites “a cold climate winter condition heat demand of a heat reclaim exchanger” and “said cold climate winter condition heat demand, to absorb heat from the CO2 refrigerant in the gas cooling stage”. The use of the definite article “said” suggests that the both heat demands refer to the same demand; however the description of the heat demands being of a the heat reclaim exchanger and the absorption of heat in the gas cooling stage suggest different demands. Thus it is conflicting if the demands are the same or different demand rendering the scope of the claim to be indefinite. Claim 1 recites “for a cold climate winter condition heat demand…” however this limitation is unclear. It is unclear if by mere operation (e.g. operation of the compressor and pressure-regulating device) in a transcritical level satisfies the claim. Claims depending from a rejected claim are rejected due to their dependency. Prior art discussion There is substantial confusion as to the scope of the claims for the reasons stated above. For this reason it is not appropriate to apply a prior art rejection as such would require considerable speculation. Nonetheless the following discussion of prior art is provided for applicant to consider in an effort towards compact prosecution. The following discussion is adapted from the prior art rejection of the last office action (dated 8/28/2025). Listing of art: Christensen (WO 2007/022778), Nilsson et al (“Ice Rink Refrigeration System with Carbon Dioxide as Secondary Fluid in Copper Tubes” reference provided by applicant on IDS received 7/6/2020), and Concha et al (US 7,225,629). Regarding claim 1, Christensen discloses (refer to figure 5 unless otherwise noted) a method for operating a CO2 refrigeration system, comprising: operating a refrigeration cycle by sequentially: compressing CO2 refrigerant (with compressor 14), releasing heat from the CO2 refrigerant in a gas cooling stage (within gas cooler 18) after the compressing, absorbing heat from a target (at heat exchanger 30 cooling is performed) after the releasing, and directing the CO2 refrigerant having absorbed heat to the compressing; and for a heat demand of a heat reclaim heat exchanger (22; it is noted here that valve 20 may be downstream of 22, 4:15-16) in heat exchange relation with a circuit including a heat transfer fluid (“thermal medium” 5:26), causing the pressure of the CO2 refrigerant to reach a transcritical level (figures 3 and 4 show transcritical operation) as a function of said heat demand and regardless of a refrigeration load to absorb heat from the CO2 refrigerant after the compressing and before the absorbing by controlling the compressing and/or controlling a pressure regulating device (20 and/or 28) downstream of the gas cooling stage, (page 3, lines 10-18 discusses transitioning to transcritical operation based on ambient temperature or in other words the demand or capacity of ambient to dissipate heat; page 5, lines 25-36 describe transitioning between subcritical and transcritical by charging or discharging the capacity of storage tank 40 which reflects the demand of heat reclaim units 50 and 22; page 6, lines 6-13 describe transitioning from sub-critical to transcritical operation caused by seasonal changes and includes a change in heat reclaim demand) the heat reclaim exchanger for reclaiming waste heat. Moreover as Christensen is operating in the transcritical level and reclaiming heat that a heat demand is satisfied. Further regarding, in the alternative, a heat demand of the heat reclaim units. Concha discloses a CO2 refrigeration heat pump including a heat reclaim unit which causes the pressure of the CO2 refrigerant to reach a transcritical level as a function of heat demand (steps 201 and 202 provide for a heat demand, based on the temperature of the tank, and energizing the heat pump which puts the refrigerant at a transcritical level). It would have been obvious to one of ordinary skill in the art to have provided Christensen with an additional heat reclaim unit for heating a water tank including the operation of the heat pump based on demand as taught by Concha in order to provide for supply of hot water, usable for domestic purposes or for space heating. Christensen lacks the use of the CO2 system being for an “ice-playing surface”. Nilsson discloses that it is known to utilize CO2 refrigeration systems for the cooling of ice rinks. It has been held that combining prior art elements according to known methods to yield predictable results is obvious. In this instance Christensen provides the base CO2 refrigeration system is known and Nilsson provides that the cooling of an ice playing surface by CO2 is known. It is therefor recognized that combining Christensen and Nilsson achieves the predictable result of performing cooling and is obvious. Christensen discloses causing the pressure of the CO2 refrigerant to reach a transcritical level as a function of said heat demand includes causing the pressure of the CO2 refrigerant to reach a pressure of at least 1400 psi (page 5 “120 bar” which is about 1740 psi and thus at least 1400 psi). Christensen is silent concerning transcritical operation during winter months. Christensen does provide for winter operation in the subcritical regime (page 6, lines 6-7), but notes the transition to transcritical based on the temperature of heat release (page 1, lines 8-23). Further the high side of the system is used to heat a heating system in winter time (page 6, lines 9-10). Therefor it would have been obvious to one of ordinary skill in the art to have operated the system in the transcritical regime in order to allow for higher heating temperatures during winter operation. Regarding claim 2, Christensen discloses causing the pressure of the CO2 refrigerant to return to a subcritical level from said transcritical level as a function of said heat demand (Christensen provides for sub-critical operation; Concha provides for the determination of demand, thus if demand is not required for water heating on Concha the modified Christensen is free to operate in the subcritical regime. Regarding claim 3, Christensen discloses causing the pressure of the CO2 refrigerant to reach a transcritical level includes controlling the pressure regulating device (20 and/or 28) downstream of the gas cooling stage (18). Regarding claim 4, Christensen discloses accumulating CO2 refrigerant in a liquid state in a reservoir (12) prior to said absorbing heat (at 30). Regarding claim 5, Christensen and Nilsson disclose absorbing heat from at least one ice-playing surface includes circulating CO2 refrigerant in a circuit of pipes to absorb heat from the at least one ice-playing surface (figure 2 of Nilsson provides for pipes to absorb heat from the ice playing surface). Regarding claim 6, Christensen and Nilsson circulating CO2 refrigerant in a circuit of pipes includes vaporizing the CO2 refrigerant with at least one expansion valve (28 of Christensen). Regarding claim 9, Christensen discloses the secondary refrigerant heats water in at least one water tank (40; page 6, lines 8-9). Regarding claim 10, Christensen discloses heat reclaim exchanger (22) absorbs heat from the CO2 refrigerant in series with the gas cooling stage (50 and 22 are in series with 18 as shown in figure 5). Regarding claim 11, Christensen discloses the heat reclaim heat exchanger (22) absorbs heat from the CO2 refrigerant in the gas cooling stage in series rather than parallel. In a previous office action on the merits the Examiner took Official Notice that arranging heat exchangers in parallel is old and well known. In his subsequent reply to this office action, the applicant did not traverse Examiner’s assertion of Official Notice with regard to these elements. Therefore the Official Notice statements by the Examiner regarding these elements are now taken as admitted prior art by Applicant. See MPEP §2144.03(C). It would have been obvious to one of ordinary skill in the art to have rearranged the heat reclaim heat exchanger of Christensen (22) to be in parallel with 18 rather than series in order to reduce pressure drop and thereby reduce pumping requirements. Regarding claim 12, Christensen discloses heat is released from the CO2 refrigerant by blowing air on a coil (18) which circulates the CO2 refrigerant (figure 5 shows a fan at coil 18 for releasing). Regarding claims 13 and 14, Christensen discloses the method of claim 1 but is silent concerning oil. In a previous office action on the merits the Examiner took Official Notice that that collecting oil in a reservoir at a compressor outlet and returning oil to a compressor inlet is old and well known. In his subsequent reply to this office action, the applicant did not traverse Examiner’s assertion of Official Notice with regard to these elements. Therefore the Official Notice statements by the Examiner regarding these elements are now taken as admitted prior art by Applicant. See MPEP §2144.03(C). It would have been obvious to one of ordinary skill in the art to have provided Christensen with an oil separator in order to maintain lubrication within the compressor and reduce lubricant fouling of the heat exchangers. Regarding claim 15, Christensen discloses controlling the pressure-regulating device downstream of the gas cooling stage includes modulating a valve (20 or 28) to maximize the heat reclaim as a function of the heat demand (pages 4-5 and figures 2-4 describe the change in COP and heat reclaim in the 2-3 enthalpy change). Regarding claim 17, Christensen discloses causing the pressure of the CO2 refrigerant to reach a transcritical level as a function of said heat demand includes causing the pressure of the CO2 refrigerant to reach a pressure of about 580 psi (“40 bar” page 5, line 20) as a function of the heat demand during a summer month period, wherein an outdoor temperature is warmer in the summer month period than in the winter month period (page 1, lines 8-23). While the cited section discusses transition to transcritical operation during summer months; it is understood that the temperature in the summer months won’t always be above 20C and therefor during these times the system operates in the subcritical range in order to increase COP as disclosed. Further regarding the claimed pressure of 550 psi vs the disclosed pressure of 580 psi; it has been held that the optimization of a result-effective variable is obvious. In this instance condensing pressure during subcritical operation relates to system COP. Therefor because pressure is recognized as effecting the result of COP; the value of 550 psi is not a product of innovation but of ordinary skill and is obvious to optimize in order to improve COP. Response to Arguments Applicant’s arguments filed 11/28/2025 have been fully considered but are not persuasive. For the reasons stated above the scope of the claims is not clear. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Backman et al (US 6,321,551) utilizes heat from cooling rink for facility heating. 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 CHRISTOPHER R ZERPHEY whose telephone number is (571)272-5965. The examiner can normally be reached M-F 7:00-4:00 PM. 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, Jianying Atkisson can be reached on 5712707740. 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. /CHRISTOPHER R ZERPHEY/Primary Examiner, Art Unit 3763
Read full office action

Prosecution Timeline

Mar 05, 2020
Application Filed
Jan 26, 2022
Non-Final Rejection — §112, §DP
May 02, 2022
Response Filed
May 09, 2022
Final Rejection — §112, §DP
Aug 10, 2022
Request for Continued Examination
Aug 16, 2022
Response after Non-Final Action
Aug 25, 2022
Non-Final Rejection — §112, §DP
Nov 30, 2022
Response Filed
Dec 02, 2022
Applicant Interview (Telephonic)
Dec 02, 2022
Examiner Interview Summary
Dec 12, 2022
Final Rejection — §112, §DP
Feb 15, 2023
Response after Non-Final Action
Feb 28, 2023
Response after Non-Final Action
Apr 17, 2023
Response after Non-Final Action
Apr 17, 2023
Notice of Allowance
May 04, 2023
Response after Non-Final Action
Jun 17, 2023
Response after Non-Final Action
Jun 19, 2023
Response after Non-Final Action
Jun 26, 2023
Response after Non-Final Action
Jun 30, 2023
Response after Non-Final Action
Jul 14, 2023
Response after Non-Final Action
Jul 20, 2023
Response after Non-Final Action
Aug 07, 2023
Response after Non-Final Action
Oct 18, 2023
Response after Non-Final Action
Oct 18, 2023
Response after Non-Final Action
Oct 19, 2023
Response after Non-Final Action
Oct 19, 2023
Response after Non-Final Action
Jun 12, 2025
Response after Non-Final Action
Aug 13, 2025
Request for Continued Examination
Aug 15, 2025
Response after Non-Final Action
Aug 27, 2025
Non-Final Rejection — §112, §DP
Nov 28, 2025
Response Filed
Dec 09, 2025
Final Rejection — §112, §DP
Mar 11, 2026
Request for Continued Examination
Apr 01, 2026
Response after Non-Final Action
Apr 10, 2026
Non-Final Rejection — §112, §DP (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

7-8
Expected OA Rounds
48%
Grant Probability
67%
With Interview (+19.1%)
3y 1m
Median Time to Grant
High
PTA Risk
Based on 749 resolved cases by this examiner. Grant probability derived from career allow rate.

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