DETAILED ACTION
Response to Amendment
The Amendment filed January 5, 2026 has been entered. Claims 1 – 4 and 6 – 19 are pending in the application with claims 12 – 19 being newly added, claims 2, 3, 6 – 8 and 10 being withdrawn, and claim 5 being cancelled. The amendment to the claims has overcome the claim objections set forth in the last Non-Final Action mailed October 3, 2025.
Claim Objections
Claims 11 – 19 are objected to because of the following informalities:
Claim 11, line 4: “arranging permanent magnets” should read --arranging permanent magnets--. Claim 11 was amended and this change was not reflected correctly. See MPEP 714 II C (B).
Claim 11, line 5: “arranging electromagnets” should read --arranging electromagnets--. Claim 11 was amended and this change was not reflected correctly. See MPEP 714 II C (B).
Claim 11, lines 7-8: “exerted by the permanent magnets and the electromagnets” should read --exerted by the permanent magnets and the electromagnets--. Claim 11 was amended and this change was not reflected correctly. See MPEP 714 II C (B).
Claim 12, line 1: “Reciprocating equipment” should read --A reciprocating equipment--.
Claim 12, line 4: “couple” should read --coupled--.
Claim 12, line 11: “the second of” should read --the second side of--.
Claims 13 – 19 are objected to for being dependent on claim 12.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 4, 9 and 11 – 19 are rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al. (CN 103994051 – herein after Cheng) in view of Nefzi et al. (US 2016/0216611 – herein after Nefzi).
In reference to claim 1, Cheng teaches a compressor (see fig. 2), comprising:
a piston (11) comprising a first rod (8) and an extension rod (15) connected to the first rod, the extension rod having a first side (one of left or right side in view of fig. 2 or one of top or bottom side in view of fig. 4) and a second side (other of the left or right side in view of fig. 2 or other of the top or bottom side in view of fig. 4), opposing one another;
a crankcase assembly (1+2+3) connected to the first rod (8);
a cylinder (10); and
a magnetic bearing (19) configured to support movement of the piston (11) sliding into the cylinder.
Cheng does not teach the compressor, wherein magnetic bearing comprises “permanent magnets” arranged on the first side of the extension rod of the piston and “electromagnets” arranged on the second side of the extension rod of the piston, wherein the permanent magnets and the electromagnets exert a fixed magnetic force and a variable magnetic force, respectively, to support the piston during its movement, wherein the fixed magnetic force and the variable magnetic force are arranged to generate a repulsive force and an attractive force in a direction perpendicular to the extension rod of the piston, and wherein the direction of the repulsive force and the attractive force is the same.
However, Nefzi teaches (see ¶51 or abstract) a weight compensating device (202) using a first magnetic device (204) and a second magnetic device (206). Nefzi uses (see ¶51-¶53 and ¶74-¶75) permanent magnets (210, 214) to provide a base magnetic force and incorporates an actuator (902) with a coil (904) to provide an adjustable/variable magnetic force. These magnetic forces are arranged on opposing sides (230, 232) of the supported component to maintain stability.
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 provision of magnets in Cheng’s compressor for “permanent magnets arranged on the first side of the extension rod of the piston and electromagnets arranged on the second side of the extension rod of the piston” utilizing the teaching of Nefzi for enhanced precision and energy efficiency. Cheng teaches (see ¶5 in translation) that in horizontal reciprocating compressors, the weight of the piston assembly creates lateral forces that cause wear and inefficiency. A person having ordinary skill in the art (PHOSITA) would recognize that in such a horizontal orientation, Cheng’s extension rod (15) and piston assembly function as a load requiring gravity compensation, which is functionally equivalent to the component (126) supported by the weight compensating device (202) of Nefzi. By applying Nefzi’s teaching, the PHOSITA would use permanent magnets to provide a fixed baseline force to counteract the constant weight of the horizontal piston assembly, thereby reducing the power required by the electromagnets. Simultaneously, the electromagnets would provide the variable force necessary for active, high-precision centering during high-speed reciprocating movement.
With respect to the limitations “wherein the permanent magnets and the electromagnets exert a fixed magnetic force and a variable magnetic force, respectively, to support the piston during its movement, wherein the fixed magnetic force and the variable magnetic force are arranged to generate a repulsive force and an attractive force in a direction perpendicular to the extension rod of the piston, and wherein the direction of the repulsive force and the attractive force is the same”: It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to arrange these forces to act in the same direction – pushing from one side and pulling from the other – as a matter of design choice to achieve cumulative stabilization, effectively summing the forces to support the piston assembly. A PHOSITA would understand that coordinating these forces to be additive (summing their magnitudes along the same vector) is a routine engineering variation used to achieve a desired technical effect: maximized supporting force and improved centering precision. Choosing a “push-pull” configuration over other arrangements is merely the optimized application of basic magnetic principles to meet the specific load requirements of a reciprocating piston rod. Furthermore, it is to be noted that applicant has not disclosed any criticality associated with this claimed arrangement of magnetic forces.
In reference to claim 4, Cheng, as modified, teaches the compressor according to claim 1, wherein the permanent magnets face each other with the same polarity so as to generate the repulsive force (inherent feature in view of the proposed modification discussed above in claim 1).
In reference to claim 9, Cheng, as modified, teaches the compressor according to claim 1, wherein the cylinder (10; in Cheng) is a horizontal cylinder (frame of reference when Cheng’s fig. 2 is rotated clockwise by 90° or see Cheng’s ¶5 in translation).
In reference to claim 11, Cheng teaches a method, comprising:
arranging a piston (11) sliding into a cylinder (10) on a compressor (seen in fig. 2), the piston comprising a first rod (8) that connects to a crankcase assembly (1+2+3) and an extension rod (15) connected to the first rod,
wherein movement of the piston is supported by means of a magnetic bearing (19).
Cheng does not teach the method comprising: arranging permanent magnets on a first side (one of left or right side in view of fig. 2 or one of top or bottom side in view of fig. 4) of the extension rod (15) of the piston (11); arranging electromagnets on a second side (other of the left or right side in view of fig. 2 or other of the top or bottom side in view of fig. 4) of the extension rod (15) of the piston (11) opposite of the first side, wherein movement of the piston is supported by means of magnetic forces exerted by the permanent magnets and electromagnets, respectively, and wherein the direction of the repulsive force and the attractive force is the same.
However, Nefzi teaches (see ¶51 or abstract) a weight compensating device (202) using a first magnetic device (204) and a second magnetic device (206). Nefzi uses (see ¶51-¶53 and ¶74-¶75) permanent magnets (210, 214) to provide a base magnetic force and incorporates an actuator (902) with a coil (904) to provide an adjustable/variable magnetic force. These magnetic forces are arranged on opposing sides (230, 232) of the supported component to maintain stability.
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 provision of magnets in Cheng’s compressor for permanent magnets arranged on the first side of the extension rod of the piston and electromagnets arranged on the second side of the extension rod of the piston opposite of the first side utilizing the teaching of Nefzi for enhanced precision and energy efficiency. Cheng teaches (see ¶5 in translation) that in horizontal reciprocating compressors, the weight of the piston assembly creates lateral forces that cause wear and inefficiency. A person having ordinary skill in the art (PHOSITA) would recognize that in such a horizontal orientation, Cheng’s extension rod (15) and piston assembly function as a load requiring gravity compensation, which is functionally equivalent to the component (126) supported by the weight compensating device (202) of Nefzi. By applying Nefzi’s teaching, the PHOSITA would use permanent magnets to provide a fixed baseline force to counteract the constant weight of the horizontal piston assembly, thereby reducing the power required by the electromagnets. Simultaneously, the electromagnets would provide the variable force necessary for active, high-precision centering during high-speed reciprocating movement.
With respect to the limitations “wherein movement of the piston is supported by means of magnetic forces exerted by the permanent magnets and electromagnets, respectively, and wherein the direction of the repulsive force and the attractive force is the same”: It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to arrange these forces to act in the same direction – pushing from one side and pulling from the other – as a matter of design choice to achieve cumulative stabilization, effectively summing the forces to support the piston assembly. A PHOSITA would understand that coordinating these forces to be additive (summing their magnitudes along the same vector) is a routine engineering variation used to achieve a desired technical effect: maximized supporting force and improved centering precision. Choosing a “push-pull” configuration over other arrangements is merely the optimized application of basic magnetic principles to meet the specific load requirements of a reciprocating piston rod. Furthermore, it is to be noted that applicant has not disclosed any criticality associated with this claimed arrangement of magnetic forces.
In reference to claim 12, Cheng teaches a reciprocating equipment (see fig. 2), comprising:
a crank case assembly (1+2);
a cross-head (3) coupled to the crank case assembly (1+2);
a cylinder (10) coupled (indirectly coupled or operationally coupled) to the cross-head (3);
a piston (11) disposed in the cylinder, the piston having a top and a bottom (as evident from fig. 2);
a first rod (8) coupled to the bottom of the piston, the first rod connecting the piston to the cross-head;
a second rod (15) coupled to the top of the piston at a first end (bottom end of the second rod), the second rod having a first side (one of left or right side in view of fig. 2 or one of top or bottom side in view of fig. 4) and a second side (other of the left or right side in view of fig. 2 or other of the top or bottom side in view of fig. 4); and
a magnetic bearing (19) disposed in proximity (vicinity) to a second end (top end) of the second rod (15),
wherein the magnetic bearing generates magnetic fields on the first side and the second side of the second rod (inherent feature).
Cheng does not teach the reciprocating equipment, wherein the magnetic fields are arranged to generate a repulsive force and an attractive force in a direction perpendicular to the second rod, and wherein the direction of the repulsive force and the attractive force is the same.
However, Nefzi teaches (see ¶51 or abstract) a weight compensating device (202) using a first magnetic device (204) and a second magnetic device (206). Nefzi uses (see ¶51-¶53 and ¶74-¶75) permanent magnets (210, 214) to provide a base magnetic force and incorporates an actuator (902) with a coil (904) to provide an adjustable/variable magnetic force. These magnetic forces are arranged on opposing sides (230, 232) of the supported component to maintain stability.
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 provision of magnets in Cheng’s compressor for “permanent magnets arranged on the first side of the extension rod of the piston and electromagnets arranged on the second side of the extension rod of the piston” utilizing the teaching of Nefzi for enhanced precision and energy efficiency. Cheng teaches (see ¶5 in translation) that in horizontal reciprocating compressors, the weight of the piston assembly creates lateral forces that cause wear and inefficiency. A person having ordinary skill in the art (PHOSITA) would recognize that in such a horizontal orientation, Cheng’s extension rod (15) and piston assembly function as a load requiring gravity compensation, which is functionally equivalent to the component (126) supported by the weight compensating device (202) of Nefzi. By applying Nefzi’s teaching, the PHOSITA would use permanent magnets to provide a fixed baseline force to counteract the constant weight of the horizontal piston assembly, thereby reducing the power required by the electromagnets. Simultaneously, the electromagnets would provide the variable force necessary for active, high-precision centering during high-speed reciprocating movement.
With respect to the limitations “wherein the magnetic fields are arranged to generate a repulsive force and an attractive force in a direction perpendicular to the second rod, and wherein the direction of the repulsive force and the attractive force is the same”: It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to arrange these forces to act in the same direction – pushing from one side and pulling from the other – as a matter of design choice to achieve cumulative stabilization, effectively summing the forces to support the piston assembly. A PHOSITA would understand that coordinating these forces to be additive (summing their magnitudes along the same vector) is a routine engineering variation used to achieve a desired technical effect: maximized supporting force and improved centering precision. Choosing a “push-pull” configuration over other arrangements is merely the optimized application of basic magnetic principles to meet the specific load requirements of a reciprocating piston rod. Furthermore, it is to be noted that applicant has not disclosed any criticality associated with this claimed arrangement of magnetic forces.
In reference to claim 13, Cheng, as modified, teaches the reciprocating equipment according to claim 12, wherein the attractive force is variable (inherent feature in view of the proposed modification discussed above in claim 12).
In reference to claim 14, Cheng, as modified, teaches the reciprocating equipment according to claim 12, wherein the attractive force results from electromagnets (“electromagnets” being present in view of the proposed modification discussed above in claim 12).
In reference to claim 15, Cheng, as modified, teaches the reciprocating equipment according to claim 12, wherein the repulsive force is constant (inherent feature in view of the proposed modification discussed above in claim 12).
In reference to claim 16, Cheng, as modified, teaches the reciprocating equipment according to claim 12, wherein the repulsive force results from permanent magnets (“permanent magnets” being present in view of the proposed modification discussed above in claim 12).
In reference to claim 17, Cheng, as modified, teaches the reciprocating equipment according to claim 12, wherein the repulsive force is different from the attractive force (inherent feature in view of the proposed modification discussed above in claim 12).
In reference to claim 18, Cheng, as modified, teaches (see Cheng’s fig. 2 and ¶2 in translation) a compressor comprising the reciprocating equipment of claim 12.
In reference to claim 19, Cheng, as modified, teaches a horizontally balanced compressor (frame of reference when Cheng’s fig. 2 is rotated clockwise by 90° or see Cheng’s ¶5 in translation) comprising the reciprocating equipment of claim 12.
Response to Arguments
The arguments filed January 5, 2026 have been fully considered but they are moot. The amendment to independent claims 1 and 11 changed the scope of the claim. As a result, the prior arts have been re-evaluated and re-applied to these claims, in view of newly relied upon reference of Nefzi.
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
/BRYAN M LETTMAN/Primary Examiner, Art Unit 3746
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