Notice of Pre-AIA or AIA Status
The present application is being examined under the pre-AIA first to invent provisions.
The claims received 3/11/2026 are entered. Claims 7-8 and 16 are cancelled. Claim 18 is new.
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 17-18 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 of winter months”. 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 directed to the at least one coil” is unclear. “the excess heat” has no antecedent basis.
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), Concha et al (US 7,225,629), and Memory et al (US 6,848,268).
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.
Regarding claim 18, Christensen lacks a suction line accumulator. Memory discloses a CO2 refrigeration cycle including recuperating oil from a suction accumulator (150) and feeding a mixture of oil and CO2 refrigerant to the compressor (6:48-58). It would have been obvious to one of ordinary skill in the art to have provided Christensen with an accumulator and oil return of Memory in order to store refrigerant at suction side and sufficiently lubricate the compressor.
Response to Arguments
Applicant’s arguments filed 3/11/2026 have been fully considered but are not persuasive.
Regarding “Priority” applicant provides no evidence/argument in support of his position
Regarding 112.2 the amendment does not clarify the demand of the claim. It is not clear to what “a cold climate winter condition of winter months heat demand of a heat reclaim exchanger”. Applicant attempts to explain “colder ambient temperatures, most often below freezing point”. This phrase is not in the original disclosure. Moreover the phrase is still ambiguous. It is not limited to below freezing.
For the reasons stated above the scope of the claims is not clear.
Regarding prior art, applicant alleges differences between the instant application and the cited prior art. However, ultimately it must be resolved if the claims define over the prior art. Due to the ambiguity of the claim scope such a determination cannot be made.
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.
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.
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/CHRISTOPHER R ZERPHEY/Primary Examiner, Art Unit 3763
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