DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55, which papers have been placed of record in the file. Claims 21 – 40 are entitled to a priority date of May 9, 2022.
Specification
The disclosure is objected to because of the following informalities:
Page 6, Line 17: “rotor casing 16” should be corrected to “rotor casing 12”
Appropriate correction is required.
Claim Objections
Claims 21 – 38 are objected to because of the following informalities:
Claim 21, Line 8 should be corrected to “…each of said valves being moveable…”
Claims 22 – 38 should all start “The discharge plate according to…” since they are all dependent claims.
Appropriate correction is required.
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.
Claims 24 – 33 and 35 – 39 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 24 recites two circular openings for accommodating the rotor shafts. The metes and bounds of the claim are unascertainable because Claim 23, upon which Claim 24 depends, already introduces a plurality of circular opening each configured to accommodate a rotor shaft. It is unclear whether Claim 24 requires additional circular openings or merely refers to the same openings introduced in Claim 23. For purposes of examination, the circular openings of Claim 24 will be interpreted as being part of the plurality of circular openings introduced in Claim 23. Examiner suggests amending to …wherein the plurality of circular openings comprise two circular openings, a first circular opening…
Claim 24 recites a male screw rotor and a female screw rotor. The metes and bounds of the claim are unascertainable because Claim 21, upon which Claim 24 depends, already introduces a plurality of rotatable screw rotors. It is unclear whether the language of Claim 24 requires new screw rotors for the male and female rotors or the recited male and female rotors are part of the plurality introduced in Claim 21. For purposes of examination, the male and female rotors will be interpreted as being part of the plurality introduced in Claim 21. Examiner suggests amending to …a male screw rotor of the plurality of rotatable screw rotors… and likewise for the female rotor.
Claims 29 and 31 recite the phrase at least approximately. The metes and bounds of the claim are unascertainable because it is unclear what a range of at least approximately is. For purposes of examination, the claims will be interpreted as reciting just approximately.
Claim 33 recites a group of slots. The metes and bounds of the claim are unascertainable because Claim 21, upon which Claim 33 depends, already recites pressure balancing ports, and it is unclear whether the slots of Claim 33 are the same as the pressure balancing ports or different slots. For purposes of examination, the slots in Claim 33 will be interpreted as being the same as the pressure balancing ports of Claim 21.
Claim 35 recites a first and second array of discharge ports. The metes and bounds of the claim are unascertainable because Claim 21, upon which Claim 35 depends, already recites pressure balancing ports, and it is unclear whether the discharge ports of Claim 35 are the same as the pressure balancing ports or different ports. The disclosure only uses the term “discharge port” for a single port downstream of the discharge chamber, and any array arrangement, as recite din Claim 35 is attributed to the pressure balancing ports. For purposes of examination, the discharge ports in Claim 35 will be interpreted as being the same as the pressure balancing ports of Claim 21.
Claim 35 recites said first circular opening and said second circular opening. The metes and bounds of the claim are unascertainable because these terms lack antecedent basis. The terms are first introduced in Claim 24, which is not in the dependency branch of Claim 35. For purposes of examination, Claim 35 will be treated as if it depended on Claim 24.
Claim 39 recites a rotor hosing, an outlet housing, and a discharge chamber. The metes and bounds of the claim are unascertainable because Claim 39 is dependent on Claim 21, which already introduces all of these components, making their recitation Claim 39 unclear as to whether additional components are needed. For purposes of examination, the claims will be interpreted as reciting the rotor hosing, the outlet housing, and the discharge chamber.
Claims 25 – 28, 30, 32, 34, and 36 – 38 are all rejected by virtue of their dependence on one of the rejected claims above.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 21 – 25, 39, and 40 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Broglia et al. (hereafter “Broglia” – US 2021/0131434).
With regards to Claims 21 and 40:
Broglia discloses a screw machine and a discharge plate for the screw machine (Figures 8 – 14), said rotating screw machine comprising:
a rotor housing (housing 11) defining an internal cavity (compression chamber 6) in which a plurality of rotatable screw rotors (screw elements 8’, 8’’) are located, and an outlet casing (unlabeled, see Figures 8 – 14, casing defining delivery chamber 4) defining a discharge chamber (delivery chamber 4), wherein:
said screw machine is selected from: a screw compressor (see abstract: screw compressor), a helical twin-screw compressor, an internally geared compressor, a twin-screw pump, a twin screw vacuum pump, a twin screw liquid pump, a twin screw pump for a mixture of liquids and solids, an internally geared pump, an internally geared vacuum pump, an internally geared liquid pump, and an internally geared pump for a mixture of liquids and solids;
said discharge plate (delivery plate 9, note that as per Figures 8 – 14, delivery plate 9 is a separate element from the outlet casing) is configured to define a plurality of pressure balancing ports (primary discharge port 7’, secondary discharge ports 7’’) that each provide a passageway through the discharge plate, and
said discharge plate further comprises a plurality of valves (moveable elements 14) coupled to a face of the discharge plate, each said valve being moveable between a position where the valve closes one or more of the pressure balancing ports (see position in Figure 8) and a position where the valve opens one or more of the pressure balancing ports (see position in Figure 9);
wherein the pressure balancing ports and valves are arranged so that in response to a pressure difference the valves can open into the discharge chamber to open one or more of said pressure balancing ports when the discharge plate is coupled between the rotor housing and outlet housing of the rotating screw machine and thereby provide one or more passageways between the rotor housing and the discharge chamber that enable pressure balancing to occur between the internal cavity of the rotor housing and the discharge chamber, the discharge plate being configured so that fluid can pass from the rotor housing to the discharge chamber only via one or more of said passageways when compression pockets between the plurality of rotatable screw rotors align with said pressure balancing ports (see abstract: “The adjustment system includes a mechanical valve interposed between the compression chamber and the delivery chamber that automatically varies discharge port apertures in response to a pressure differential between delivery chamber and compression chamber to instantaneously equalize compression and and [sic] delivery pressure and improve compressor efficiency”, see also Paragraphs 99 – 104).
With regards to Claim 22:
Broglia discloses a shaped opening primary discharge port 78’, see Figures 13, 14) defining a passageway through the discharge plate, the shaped opening having a size and shape that is configured to define a maximum allowable internal volume ratio in the rotating screw machine (see Paragraphs 100 – 104).
With regards to Claim 23:
Broglia discloses a plurality of circular openings (see Figure 13, openings corresponding to axes X1, X2), each configured to accommodate a rotor shaft of a said rotor of said plurality of rotatable screw rotors (see unlabeled shafts in Figure 12).
With regards to Claim 24:
Broglia discloses two circular openings (see Figure 13, openings corresponding to axes X1, X2), a first circular opening for accommodating the rotor shaft of a male screw rotor (male screw element 8’) and a second circular opening for accommodating the rotor shaft of a female screw rotor (female screw element 8’’), the male and females screw rotors being mechanically meshed together so that rotation of one screw rotor in a first direction causes another to rotate in a second direction opposite to the first direction (Paragraph 55, see also Figure 12).
With regards to Claim 25:
Broglia discloses the pressure balancing ports comprise slots (see Figures 13, 14, the secondary openings 7’’ qualify as “slots” under broadest reasonable interpretation).
With regards to Claim 39:
Broglia discloses a screw machine (Figures 8 – 14) in combination with a discharge plate (delivery plate 9) according to Claim 21, the screw machine comprising a rotor housing (housing 11) and an outlet housing (unlabeled, see Figures 8 – 14, casing defining delivery chamber 4), said discharge plate being provided between the rotor housing and the outlet housing (as shown in Figures 8, 9) and arranged so that the valves (moveable elements 14) of the discharge plate can open into a discharge chamber (discharge chamber 4) of said outlet housing in operation of said screw machine (see Figures 8, 9).
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 of this title, 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.
Claims 25 – 32 and 35 – 38 are rejected under 35 U.S.C. 103 as being unpatentable over Broglia et al. (hereafter “Broglia” – US 2021/0131434).
With regards to Claim 25:
Broglia does not explicitly disclose the pressure balancing ports comprise slots, in that the openings are long, narrow openings. However, the courts have held that a change in form or shape is generally recognized as being within the level of ordinary skill in the art, absent any showing of unexpected results, see In re Dailey et al., 149 USPQ 47. In another embodiment (Figures 2 – 7), Broglia teaches the openings being more “slot” shaped (see Figures 6, 7, and Paragraph 51 describing them as “slits”). These slits perform the same exact function as the openings in the embodiment of Figures 8 – 14 relied on for the rejection of Claim 21 in that they direct compressed fluid from the compression chamber to the discharge chamber. Given the above, it would have been obvious to one of ordinary skill in the art to modify the openings of Broglia by making them “slot” shaped in order to yield the predictable result of having them continue to direct compressed fluid from the compression chamber to the discharge chamber.
With regards to Claims 26 and 35:
The Broglia modification of Claim 25 does not explicitly teach a first array of slots associated with said first circular opening, and a second array of slots associated with said second circular opening. Figures 13 and 14 of Broglia appear to only teach an array on one of the circular openings. However, Paragraph 98 of Broglia does teach that the three secondary discharge openings are only an example of what may be provided. In another embodiment (Figures 2 – 7), Broglia teaches the secondary discharge openings being located on both the male and female sides of the screw machine. Given that the compressed fluid traverses both the male and female rotors and compression pockets exist on both rotors, one of ordinary skill in the art would have found it obvious to modify Broglia of Figures 8 – 14 by adding openings to both circular openings corresponding to the shafts of the male and female rotors, as shown in Figures 6, 7, of Broglia, thereby equalizing compression on both sides of the screw machine, and yielding a first array of slots (“slot” shaped as per modification in Claim 25) associated with said first circular opening, and a second array of slots associated with said second circular opening.
With regards to Claim 27:
The Broglia modification of Claim 26 teaches the slots of each array extend outwardly along notional radial lines emanating from respective centers of each circular opening (see Figures 6, 7, slits 7’’, although not extending solely in a radial direction, do extend at least partially in an outwardly direction along radial lines emanating from the shaft axes X1, X2).
With regards to Claims 28 and 30:
The Broglia modification of Claim 26 teaches the first/second array of slots extend from a first radial position outside of the first/second circular opening to a second radial position further from a center of said first/second circular opening than said first radial position, respectively (see Figures 6, 7, slits 7’’, although not extending solely in a radial direction, do extend at least partially in an outwardly direction along radial lines emanating from the shaft axes X1, X2 from an inner radial position to an outer radial position).
With regards to Claims 29 and 31:
The Broglia modification of Claim 26 teaches said first radial position corresponds - at least approximately - to a minimum diameter of the male/female screw rotor, and said second radial position corresponds - at least approximately - to a maximum diameter of the male/female screw rotor, respectively (see Figure 7, where the slits are shown along the cross section of the rotors 8’, 8’’, and the inner radial end of the slits correspond to an inner/minimum diameter of the rotors and the outer radial end of the slits correspond to an outer/maximum diameter of the rotors).
With regards to Claim 32:
The Broglia modification of Claim 26 teaches each array of slots comprises one or more spaced groups of slots, and each group comprises one or more slots (see Figures 6, 7, both the male rotor and female rotor have a single array of a plurality of slits 7’’).
With regards to Claim 36:
The Broglia modification of Claim 35 teaches said first array of ports are regularly spaced around a portion of a circumference of the first circular opening and the second array of ports are regularly spaced around a portion of the circumference of the second circular opening (see Figures 6, 7, first array of ports 7’ around the male rotor 8’ are spaced about its circumference, and second array of ports 7’’ around the female rotor 8’’ are spaced about its circumference).
With regards to Claim 37:
The Broglia modification of Claim 35 teaches each valve (movable element 14) is associated with a said port and comprises a valve body movable to open or close the port with which it is associated (see Figures 8, 9 and Paragraphs 98 – 108).
With regards to Claim 38:
The Broglia modification of Claim 35 teaches each valve lies within a said port when the port is closed (see Figures 8, 9, moveable elements 14 have piston heads 19’ which fit and have valve seats within the discharge ports 7’’ when closed, see also Paragraph 97).
Claim 34 is rejected under 35 U.S.C. 103 as being unpatentable over Broglia et al. (hereafter “Broglia” – US 2021/0131434) in view of Meeusen et al. (hereafter “Meeusen” – WO 2023/214021).
With regards to Claim 34:
The Broglia modification of Claim 26 does not explicitly teach each valve comprises a reed valve. Meeusen (Figures 5, 8, 9) teaches a similar screw compressor with a discharge valve assembly, wherein the valves (500, 126, 902) that open and close the discharge ports are reed valve (Page 2, Line 26, see also Figures 5, 8, and 9). MPEP 2143B teaches it is obvious to substitute known elements for one another in order to yield predictable results. In this case, the reed valves of Meeusen and the valves of Broglia both act to open and close discharge ports on a screw compressor based on pressure differentials across the valves. It would have been obvious to one of ordinary skill in the art to modify the system of Broglia by replacing the valves shown in Figures 8, 9 with reed valves as shown in Meeusen to yield the predictable result of continuing to open and close the ports based on pressure differentials as originally intended.
Claims 21 and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Meeusen et al. (hereafter “Meeusen” – WO 2023/214021) in view of Broglia et al. (hereafter “Broglia” – US 2021/0131434)
With regards to Claims 21 and 40:
Meeusen discloses a screw machine and a discharge plate for the screw machine (Figures 1 – 9), said rotating screw machine comprising:
a rotor housing (housing 102) defining an internal cavity (chamber 122) in which a plurality of rotatable screw rotors (rotors 104, 108) are located, and a discharge chamber (see Figure 1, volume between outlet port 118 and valve assembly 112), wherein:
said screw machine is selected from: a screw compressor (Page 1, Line 5: “screw-type compressors”), a helical twin-screw compressor, an internally geared compressor, a twin-screw pump, a twin screw vacuum pump, a twin screw liquid pump, a twin screw pump for a mixture of liquids and solids, an internally geared pump, an internally geared vacuum pump, an internally geared liquid pump, and an internally geared pump for a mixture of liquids and solids;
said discharge plate (valve seat plates 132 or 304, Figures 3 – 9) is configured to define a plurality of pressure balancing ports (openings 306) that each provide a passageway through the discharge plate, and
said discharge plate further comprises a plurality of valves (valves 126 or 500 or 902) coupled to a face of the discharge plate, each said valve being moveable between a position where the valve closes one or more of the pressure balancing ports and a position where the valve opens one or more of the pressure balancing ports (see Figures 3 – 9 and Page 22, Line 25 – Page 23, Line 21);
wherein the pressure balancing ports and valves are arranged so that in response to a pressure difference the valves can open into the discharge chamber to open one or more of said pressure balancing ports when the discharge plate is coupled between the rotor housing and outlet housing of the rotating screw machine and thereby provide one or more passageways between the rotor housing and the discharge chamber that enable pressure balancing to occur between the internal cavity of the rotor housing and the discharge chamber, the discharge plate being configured so that fluid can pass from the rotor housing to the discharge chamber only via one or more of said passageways when compression pockets between the plurality of rotatable screw rotors align with said pressure balancing ports (Page 23, Lines 22+: “the cracking pressures of the valves may be determined dependent on one or more parameters selected from the group of parameters consisting of pressure difference over the valves”, see also Page 13, Line 24 – Page 14, Line 21).
Meeusen does not explicitly disclose an outlet casing, instead having a single casing for the main hosing and the outlet casing. However, the courts have held that a one piece construction and a construction made of multiple pieces are obvious variants, see In re Larson, 340 F.2d 965, 968, 144 USPQ 347, 349 (CCPA 1965). Broglia (Figures 8 – 14) teaches a similar screw compressor with a discharge valve assembly, wherein the housing is comprised of at least two casings coupled together, with an outlet casing (unlabeled, see Figures 8 – 14, casing defining delivery chamber 4) defining a discharge chamber (delivery chamber 4). Making the outlet casing separate may aid in maintenance and removal of the valve assembly of Meeusen. Given all the above, one of ordinary skill in the art would have found it obvious to modify the system of Meeusen by making the discharge chamber be formed in a separate outlet casing in order to yield the predictable benefits described above.
Allowable Subject Matter
Claim 33 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
Additional References
Please see attached PTO-892 form for additional references which are made of record but not relied upon for the current grounds of rejection.
Chen (CN 117189593) – does not qualify as prior art, however, see Figures 1 – 3, discharge plate 1, discharge ports 2.4, discharge valves 2.
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/Laert Dounis/
Primary Examiner, Art Unit 3746
Tuesday, February 3, 2026