DETAILED ACTION
Response to Amendment
The Amendment filed February 23, 2026 has been entered. Claims 1 – 20 are pending in the application with claims 17 – 20 being newly added. The amendment to the claims has overcome the 35 USC 112 rejections set forth in the last Non-Final Action mailed December 15, 2025.
Claim Objections
Claims 1 – 20 are objected to because of the following informalities:
Claim 1, in each of lines 10, 13, and 17: “working fluid” should read --the working fluid--. This is suggested to have proper antecedent basis for this limitation. Note that “a working fluid” has been recited in line 7 of the claim 1 and claims 12 and 13 (depending on claim 1) states “the working fluid”. Similar corrections are needed for independent claim 18 and its dependent claim 19 as well.
Claim 17, lines 1-2: “wherein the sleeve and the collar are fixed relative to each other and the cylinder” should read --wherein the sleeve, and the cylinder are fixed relative to each other
Claim 18, lines 5-6: “wherein the sleeve and the collar are fixed relative to each other and the cylinder” should read --wherein the sleeve, and the cylinder are fixed relative to each other
Claims 2 – 17 are objected to for being dependent claim 1.
Claims 19 and 20 are objected to for being dependent on claim 18.
Appropriate correction is required.
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.
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 and 12 – 16 are rejected under 35 U.S.C. 103 as being unpatentable over Dallai, Mauro (US 2013/0230415 – herein after Dallai) in view of Kawamura, Hideo (US 5,113,805 – herein after Kawamura).
In reference to claim 1, Dallai teaches a compressor (1, see fig. 6) comprising (see figs. 6-7):
a cylinder (cylindrical bore for piston 9 or 11);
a sleeve assembly (see fig. A below) disposed in the cylinder, the sleeve assembly including a sleeve (see fig. A below), wherein the sleeve define a plurality of ports (labeled “P” in fig. A below; see ¶72: “It is clear that the entrances 25A, 27A and the exits 25B, 27B of the supply ports 25, 27 can be in different number, shape, and dimensions, and they can be furthermore arranged at different heights in the chambers 5, 7, and 21 according to particular construction or use requirements;..”); and
a piston (9/11) disposed within the sleeve assembly, the piston movable between a first position (bottom position) and a second position (top position) and configured to compress a working fluid as the piston moves from the first position to the second position; and
a storage plenum (14A; see ¶68 and fig. 2 or fig. 6) containing the working fluid at an intermediate pressure from an intermediate-pressure source (“external high pressure supply circuit”),
wherein the piston (9/11) and the sleeve assembly (labeled “sleeve” in fig. A below) cooperate to selectively permit the working fluid at the intermediate pressure (P2) from the intermediate-pressure source to flow through the plurality of ports from the storage plenum to the cylinder,
wherein the intermediate pressure is greater than a suction pressure (P1) and less than a discharge pressure (P3) [see ¶68: “Advantageously, the inlet system 14, for supplying the coolant in the distribution chamber 21 at a distribution pressure P2 greater than the suction pressure P1 but lower than the delivery pressure P3..”], and
wherein the working fluid from the intermediate-pressure source is prevented from entering the cylinder when the piston is blocking the plurality of ports (inherent feature in view of operational state seen in fig. 6, working fluid at intermediate pressure is seen as entering left cylinder but prevented from entering right cylinder; thus, each of the piston allows entering and blocking as claimed into their corresponding cylinder).
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Fig. A: Edited fig. 6 of Dallai to show claim interpretation.
Dallai remains silent on the compressor, wherein the sleeve assembly also comprises “a collar”, wherein the sleeve and the collar cooperate to define a plurality of ports.
However, Kawamura teaches a reciprocating piston apparatus (i.e. engine), comprising a sleeve assembly (11+3) disposed in the cylinder (1), the sleeve assembly including a sleeve (11) and a collar (3), wherein the sleeve and the collar cooperate to define a plurality of ports (12, 31).
Thus, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to modify the sleeve assembly in the compressor of Dallai for including a collar as taught by Kawamura, in place of Dallai’s separate distributor piston (19), for the purpose of providing another known way of selectively opening and closing such communication ports.
In reference to claim 12, Dallai, as modified, teaches the compressor, wherein when the piston (9/11) is in the first position (for instance, position of piston 9 seen in fig. 6), the working fluid at the intermediate pressure enters the cylinder through the plurality of ports (i.e. from 25 > port of the collar > port of the sleeve > chamber 5).
In reference to claim 13, Dallai, as modified, teaches the compressor, wherein when the piston (9/11) is in the second position (for instance, position of piston 11 seen in fig. 6), the working fluid at the intermediate pressure is restricted from entering the cylinder.
In reference to claim 14, Dallai, as modified, teaches the compressor, further comprising (see Dallai) a housing (1A, see fig. 2) and a housing cover (6, see fig. 2/6) fixed to the housing.
In reference to claim 15, Dallai, as modified, teaches the compressor, wherein the housing cover (6, of Dallai) defines an intermediate-fluid port (14c, see fig. 6 of Dallai) fluidly connected to the plurality of ports (of the modified sleeve assembly), the intermediate-fluid port being configured to receive the fluid at the intermediate pressure (P2; in Dallai).
In reference to claim 16, Dallai, as modified, teaches the compressor, further comprising a valve (distributor 19, see fig. 6 of Dallai) in fluid communication with an intermediate-fluid port (14c, of Dallai), wherein the intermediate-fluid port is fluidly connected to the plurality of ports (of the modified sleeve assembly), and wherein the intermediate-fluid port is configured to receive the fluid at the intermediate pressure (P2; in Dallai).
Claims 8 – 11 are rejected under 35 U.S.C. 103 as being unpatentable over Dallai in view of Kawamura and Shibata et al. (US 2010/0006061 – herein after Shibata).
Regarding claim 8,
Dallai teaches the compressor, wherein the piston (9/11; in Dallai) includes a hollow cylindrical body including a top wall and a side wall extending perpendicularly from the top wall (as evident from fig. 6 of Dallai).
Dallai remains silent on the compressor, wherein the top wall defines a plurality of chamfered recesses.
However, Shibata teaches an engine, wherein the piston (13, see fig. 4) includes a hollow cylindrical body (in view of fig. 1: piston’s body being hollow in view of rod’s 15 and pin’s 14 connection to the piston’s body) including a top wall and a side wall extending perpendicularly from the top wall (as evident from fig. 1), and wherein the top wall (see fig. 4) defines a plurality of chamfered recesses (13d). Shibata states (see abstract, ¶33-¶35) that these chamfered recesses are provided to manipulate the squish clearance (H) and the radial width of the squish area (W). Specifically, they are used to ensure that the strength of the fluid flow remains uniform in the circumferential direction, thereby promoting better mixing and preventing non-uniform flow strength.
A skilled artisan would recognize that applying such chamfers to Dallai’s pistons would optimize the “dead volume” clearance in the compressor head – critical for compressor efficiency – while preventing mechanical interference between the piston edge and the cylinder head features. It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to modify the top wall of the piston in the compressor of Dallai for provision of chamfered recesses as taught by Shibata for the purpose of regulating fluid flow strength and clearance uniformity during the compression stroke. Furthermore, these chamfered recesses on Dallai’s pistons would smooth the transition as the piston head passes the plurality of ports (in the sleeve assembly). Instead of a sharp 90-degree edge shearing the fluid flow, chamfers would allow for a more gradual entry of the injected coolant/fluid into the chamber, reducing turbulence and improving the volumetric efficiency.
Regarding claim 9,
Dallai, as modified, teaches the compressor, wherein the plurality of chamfered recesses (in view of Shibata’s fig. 5) extend radially inward from a perimeter of the top wall at an angle relative to the side wall.
Regarding claim 10,
Dallai, as modified, teaches the compressor, wherein the plurality of chamfered recesses extends at the angle (as discussed above in claim 9).
Dallai, as modified, remains silent on the compressor, wherein the angle is greater than or equal to 15 degrees to less than or equal to 45 degrees.
It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to have the angle is greater than or equal to 15 degrees to less than or equal to 45 degrees in the modified compressor of Dallai since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Please note that in the instant application (see ¶101 in filed specification), applicant has not disclosed any criticality for the claimed range for the angle of the chamfered recesses.
Regarding claim 11,
Dallai, as modified, teaches the compressor, wherein the plurality of chamfered recesses are aligned with the plurality of ports (the chamfered recesses aligns with the plurality of ports when the top wall of the piston cover/uncovers the plurality of ports during piston’s reciprocating movement).
Claims 1 and 17 – 19 are rejected under 35 U.S.C. 103 as being unpatentable over Dallai, Mauro (US 2013/0230415 – herein after Dallai) in view of Ernest Huber (US 2,371,297 – herein after Huber).
In reference to claim 1, Dallai teaches a compressor (1, see fig. 6) comprising (see figs. 6-7):
a cylinder (cylindrical bore for piston 9 or 11);
a sleeve assembly (see fig. A above) disposed in the cylinder, the sleeve assembly including a sleeve (see fig. A above), wherein the sleeve define a plurality of ports (labeled “P” in fig. A above; see ¶72: “It is clear that the entrances 25A, 27A and the exits 25B, 27B of the supply ports 25, 27 can be in different number, shape, and dimensions, and they can be furthermore arranged at different heights in the chambers 5, 7, and 21 according to particular construction or use requirements;..”); and
a piston (9/11) disposed within the sleeve assembly, the piston movable between a first position (bottom position) and a second position (top position) and configured to compress a working fluid as the piston moves from the first position to the second position; and
a storage plenum (14A; see ¶68 and fig. 2 or fig. 6) containing the working fluid at an intermediate pressure from an intermediate-pressure source (“external high pressure supply circuit”),
wherein the piston (9/11) and the sleeve assembly (labeled “sleeve” in fig. A above) cooperate to selectively permit the working fluid at the intermediate pressure (P2) from the intermediate-pressure source to flow through the plurality of ports from the storage plenum to the cylinder,
wherein the intermediate pressure is greater than a suction pressure (P1) and less than a discharge pressure (P3) [see ¶68: “Advantageously, the inlet system 14, for supplying the coolant in the distribution chamber 21 at a distribution pressure P2 greater than the suction pressure P1 but lower than the delivery pressure P3..”], and
wherein the working fluid from the intermediate-pressure source is prevented from entering the cylinder when the piston is blocking the plurality of ports (inherent feature in view of operational state seen in fig. 6, working fluid at intermediate pressure is seen as entering left cylinder but prevented from entering right cylinder; thus, each of the piston allows entering and blocking as claimed into their corresponding cylinder).
Dallai remains silent on the compressor, wherein the sleeve assembly also comprises “a collar”, wherein the sleeve and the collar cooperate to define a plurality of ports.
However, Huber teaches a reciprocating piston apparatus (i.e. engine), comprising a sleeve assembly (liner 12+ collar 28, see fig. 1) disposed in the cylinder (11), the sleeve assembly including a sleeve (12) and a collar (28), wherein the sleeve and the collar cooperate to define a plurality of ports (as evident in fig. 1).
Dallai requires the introduction of an additional quantity of working fluid at the intermediate pressure, but notes that high translation speeds in modern compressors can drastically reduce the actual volume of fluid successfully injected (as discussed in ¶9). Huber provides a solution to this fluid-flow limitation by teaching that passages tapering in consonance with port openings favor the gradual development of flow velocity and produce a relatively smooth, unrestricted discharging/charging flow (see page 1, left col., lines 24-33). Thus, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to modify the compressor of Dallai for including a collar as taught by Huber to define the intermediate tapered fluid passages within the collar for optimizing fluid dynamics, preventing sudden pressure blasts/surges, and/or ensuring maximum volumetric efficiency during the brief window when the intermediate fluid port is uncovered in Dallai’s compressor.
In reference to claim 17, Dallai, as modified, teaches the compressor, wherein the sleeve, the collar and the cylinder are fixed relative to each other (as evident from Huber’s fig. 1, sleeve 12, collar 28 and cylinder 11 are fixed relative to each other in the finished assembly).
In reference to claim 18, Dallai teaches a compressor (1, see fig. 6) comprising (see figs. 6-7):
a cylinder (cylindrical bore for piston 9 or 11);
a sleeve assembly (see fig. A above) disposed in the cylinder, the sleeve assembly including a sleeve (see fig. A above), wherein the sleeve define a plurality of ports (labeled “P” in fig. A above; see ¶72: “It is clear that the entrances 25A, 27A and the exits 25B, 27B of the supply ports 25, 27 can be in different number, shape, and dimensions, and they can be furthermore arranged at different heights in the chambers 5, 7, and 21 according to particular construction or use requirements;..”); and
a piston (9/11) disposed within the sleeve assembly, the piston movable between a first position (bottom position) and a second position (top position) and configured to compress a working fluid as the piston moves from the first position to the second position; and
wherein the piston (9/11) and the sleeve assembly (labeled “sleeve” in fig. A above) cooperate to selectively permit the working fluid at an intermediate pressure (P2) from an intermediate-pressure source (“external high pressure supply circuit”; see ¶68 and fig. 2 or fig. 6) to enter the cylinder,
wherein the intermediate pressure is greater than a suction pressure (P1) at which the working fluid enters the cylinder when the piston is blocking fluid flow into the cylinder from the plurality of ports, and wherein the intermediate pressure is less than a discharge pressure (P3) at which the working fluid exists the cylinder [see ¶68: “Advantageously, the inlet system 14, for supplying the coolant in the distribution chamber 21 at a distribution pressure P2 greater than the suction pressure P1 but lower than the delivery pressure P3..”; also in view of operational state seen in fig. 6, working fluid at intermediate pressure is seen as entering left cylinder but prevented from entering right cylinder; thus, each of the piston allows entering and blocking as claimed into their corresponding cylinder].
Dallai remains silent on the compressor, wherein the sleeve assembly also comprises “a collar”, wherein the sleeve and the collar cooperate to define a plurality of ports, and wherein the sleeve, the collar and the cylinder are fixed relative to each other.
However, Huber teaches a reciprocating piston apparatus (i.e. engine), comprising a sleeve assembly (liner 12+ collar 28, see fig. 1) disposed in the cylinder (11), the sleeve assembly including a sleeve (12) and a collar (28), wherein the sleeve and the collar cooperate to define a plurality of ports (as evident in fig. 1), and wherein the sleeve, the collar and the cylinder are fixed relative to each other (as evident from Huber’s fig. 1, sleeve 12, collar 28 and cylinder 11 are fixed relative to each other in the finished assembly).
Dallai requires the introduction of an additional quantity of working fluid at the intermediate pressure, but notes that high translation speeds in modern compressors can drastically reduce the actual volume of fluid successfully injected (as discussed in ¶9). Huber provides a solution to this fluid-flow limitation by teaching that passages tapering in consonance with port openings favor the gradual development of flow velocity and produce a relatively smooth, unrestricted discharging/charging flow (see page 1, left col., lines 24-33). Thus, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to modify the compressor of Dallai for including a collar as taught by Huber to define the intermediate tapered fluid passages within the collar for optimizing fluid dynamics, preventing sudden pressure blasts/surges, and/or ensuring maximum volumetric efficiency during the brief window when the intermediate fluid port is uncovered in Dallai’s compressor.
In reference to claim 19, Dallai teaches the compressor, wherein the working fluid from the intermediate-pressure source is prevented from entering the cylinder when the piston is blocking the plurality of ports (inherent feature in view of operational state seen in fig. 6, working fluid at intermediate pressure is seen as entering left cylinder but prevented from entering right cylinder; thus, each of the piston allows entering and blocking as claimed into their corresponding cylinder).
Allowable Subject Matter
Claims 2 – 7 and 20 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
With respect to the claims 2 and 20, the prior arts of record alone or in combination fails to teach the claimed structure of the sleeve that specifically includes “a plurality of recesses defined in the first portion and a plurality of apertures defined in the second portion”. The closest arts considered were as follows: Bucher et al. (US 2018/0135413) teaches a cylinder sleeve (18) with an annular flange (19), a first portion (top portion) and a second portion (bottom portion); Bean et al. (US 2018/0135622) teaches a cylinder sleeve (172) with a step (198), a first portion (top portion) and a second portion (bottom portion). However, any conclusion of obviousness to arrive specifically at the claimed features of “a plurality of recesses defined in the first portion and a plurality of apertures defined in the second portion” would be based upon improper hindsight reasoning, using knowledge gleaned only from the applicant’s disclosure.
Claims 3 – 7 depend on claim 2.
Response to Arguments
The arguments filed February 23, 2026 have been fully considered:
The arguments with respect to rejection of claims under 35 USC 102 are moot in view of the amendment made to the independent claim 1.
The arguments with respect to rejection of claims under 35 USC 103 over Dallai in view of Kawamura are not found to be persuasive. As stated in the rejection above, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to modify the sleeve assembly in the compressor of Dallai for including a collar as taught by Kawamura, in place of Dallai’s separate distributor piston (19), for the purpose of providing another known way of selectively opening and closing such communication ports. It is well established that a prior art reference need not be bodily incorporated into another to establish a proper motivation to combine, and here, a person of ordinary skill in the art would have been directly motivated to streamline Dallai’s complex layout by integrating a localized, concentric sleeve assembly configuration taught by Kawamura..
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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/CHIRAG JARIWALA/Examiner, Art Unit 3746
/ESSAMA OMGBA/Supervisory Patent Examiner, Art Unit 3746
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