DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application is being examined under the pre-AIA first to invent provisions.
Election/Restrictions
Applicant’s election of Invention I, claims 52 and 54–65 in the reply filed on July 20, 2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
Claim Rejections - 35 USC § 112(b)
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.
Claim 60 is 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 60 recites:
60. A system according to claim 59, further comprising a yoke extending into the dirty air chamber away from the aperture in the tube sheet along the pulse axis, and wherein the yoke comprises two or more support beams aligned with the pulse axis, wherein the two or more support beams are arranged asymmetrically about the pulse axis, and wherein the filter element opening comprises alignment features arranged to align with two or more support beams when the filter element is in only one rotational orientation relative to the pulse axis. Emphasis added.
Claim 60 is indefinite because it is unclear if the “two or more support beams when the filter element is in only one rotational orientation” refers to the two or more support beams in “the yoke comprises two or more support beams aligned with the pulse axis.” Further clarification is required.
Claim Rejections - 35 USC § 103
The following is a quotation of pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter 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 pre-AIA 35 U.S.C. 103(a) 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 52, 54, 56–58, 63, and 64 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Reinauer, US 4,270,935 in view of Green et al., US 2004/0079231 A1 and in further view of Suzuki et al., US 2009/0100827 A1.
Regarding claim 52, Reinauer teaches a dust collector, which reads on the claimed “filtering system.” The dust collector comprises:
A housing 10 (the claimed “housing”) comprising a tube sheet 12 (the “tube sheet”) separating the housing 10 into a dirty air plenum chamber 16 (the “dirty air chamber”) and a clean air plenum chamber 14 (the “clean air chamber”). See Reinauer Fig. 1, col. 3, ll. 6–15.
An aperture 23 in the tube sheet 12 (the “aperture”), wherein air passing from the dirty air chamber 16 to the clean air chamber 14 passes through the aperture 23. See Reinauer Fig. 1, col. 3, ll. 30–35.
A compressed cleaning gas system (the “pulse generator”) positioned to deliver pulses of compressed gas through the clean air chamber 14 and into the aperture 23 in the tube sheet 12, as claimed. See Reinauer Fig. 1, col. 4, ll. 1–18. The cleaning gas system is configured to deliver the pulses along a vertical axis (the “pulse axis”) that extends from each nozzle 30 through the aperture 23 in the tube sheet 12, as claimed. Id.
A venturi conduit means 22 (the “pulse collector”) defining an interior space (the “passageway”) that extends through the venturi 22 from an opening at the bottom of the venturi 22 inside filter 20 (the “filter end opening at a filter end of the pulse collector”) to an opening at the top of the venturi 22 at the tube sheet 12 (the “tube sheet opening at a tube sheet end of the pulse collector”). See Reinauer Fig. 1, col. 3, ll. 30–35.
The top end of the venturi 22 is attached to the tube sheet 12 such that the opening at the top end of the venturi 22 is aligned with the aperture 23 such that the vertical axis extends through the opening at the bottom and the opening at the top of the venturi 22, as claimed, as seen in Fig. 1.
Air passing from the dirty chamber 16 into the clean chamber 14 through the aperture 23 in the tube sheet 12 passes through the interior of the venturi 22, as claimed. See Reinauer Fig. 1, col. 3, ll. 30–35.
The venturi 22 comprises a “filter section,” which is the lower half of the venturi 22 , as seen in Fig. 1. The venturi 22 also comprises a “pulse section,” which is the upper half of the venturi 22. Id. The “filter section” an the “pulse section” meet at a middle area (the “junction”) located between the opening at the bottom and top of the venturi 22, as claimed, as seen in Fig. 1.
The “filter section” (bottom half of the venturi 22) comprises a “filter section length” measured along the vertical axis from the “filter end opening” (opening at the bottom of the venturi 22) to the “junction” (middle of venturi 22), as claimed, as seen in Fig. 1. Also, the “pulse section” (top half of venturi 22) comprises a “pulse section length” measured along the vertical axis from the “tube sheet end opening” (opening at the top of the venturi 22) to the “junction” (middle of venturi 22), as claimed, as seen in Fig. 1.
A portion of the “passageway” (interior of venturi 22) defined by the “pulse section” (upper half of venturi 22) comprises a diameter (the “hydraulic diameter”) that increases when moving along the vertical axis from the “junction” (middle of venturi 22) to the “tube sheet opening” (opening in top of venturi 22), as seen in Fig. 1.
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Reinauer differs from claim 52 because it is silent as to the dimensions of the venturi 22. Therefore, the reference fails to provide enough information to teach “filter section length” (length of bottom half of venturi 22) and the “pulse section length” (length of top half of venturi 22) are both equal to or less than a diameter of the “filter end opening of the pulse collector” (opening at the bottom of the venturi 22), with the “filter section length” being less than or equal to the “pulse section length.”
But Green teaches an air filtration system comprising a plurality of venturis 36 with each venturi 36 receiving a pulse of compressed gas from a nozzle 50 for cleaning a filter 22. See Green Fig. 2, [0026]. Each venturi 36 has an inlet portion 54 (analogous to the top, “pulse section” of the venturi 22 in Reinauer), a throat portion 56 (analogous to the middle, “junction” of the venturi 22 in Reinauer) and an outlet portion 58 (analogous to the bottom, “filter section” of the venturi 22 in Reinauer). Id. at Fig. 4, [0027]. The axial length of the outlet portion 58 (analogous to the “filter section length”) is 3 inches and the axial length of the inlet portion 54 (analogous to the “pulse section length”) is also 3 inches. Id. at [0028]. The diameter of the outlet opening 62 of outlet portion 58 (analogous to the “hydraulic diameter of the filter end opening”) is about 9 inches. Id.
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It would have been obvious for the venturi 22 of Reinauer to have the proportions of the venturi 36 in Green because these are suitable for receiving a pulse of compressed gas for cleaning a filter.
With this modification, the “filter section length” and the “pulse section length” of the venturi 22 of Reinauer would each be 3 inches, and the “hydraulic diameter of the filter end opening” would be about 9 inches. This reads on “the filter section length and the pulse section length are both…less than a hydraulic diameter of the filter end opening” and “the filter section length is…equal to the pulse section length,” as claimed.
Reinauer also differs from claim 52 because it is silent as bottom and upper halves of the venturi 22 (the “filter section” and “pulse section”) comprising separate articles attached to each other at the junction, as claimed.
But Suzuki teaches a venturi comprising upper and lower halves that are joined together by welding. See Suzuki [0026]. It would have been obvious for the venturi 22 of Reinauer to be manufactured by welding the bottom and upper halves together because this is a suitable technique for manufacturing a venturi.
Regarding claim 54, Reinauer teaches that the interior of the venturi 22 (the “passageway defined by the filter section”) defined by the bottom half of the venturi 22 (the “filter section”) comprises “a hydraulic diameter” that remains constant when moving along the vertical axis from the middle of the venturi 22 (the “junction”) to the bottom end of the venturi 22 (the “filter end”), as claimed—because a cylinder could be drawn in the interior of the bottom half of the venturi 22, and the diameter of this cylinder would be constant from top to bottom (as it is a cylinder). Note that claim 54 fails to specify that the diameter of an entire cross-section of the passageway defined by the filter section comprises a hydraulic diameter that remains constant (instead it merely says that “a diameter” remains constant).
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Regarding claim 56, Reinauer teaches that the venturi 22 (the “pulse collector”) comprises a length measured along the vertical axis from the bottom opening (“filter end opening”) to the aperture 23 in the tube sheet 12 (the “tube sheet opening”), as seen in Fig. 1. This length reads on the “passageway length measured along the pulse axis from the filter end opening to the tube sheet opening.”
Reinauer differs from claim 56 because it is silent as to the dimensions of the device. Therefore, it fails to provide enough information to teach that the “passageway length” is equal to or greater than the hydraulic diameter of the “filter end opening” (the opening at the bottom of the venturi 22).
But the venturi 22 is designed to receive pulses of compressed gas from nozzle 30 and direct the pulses into the filter 18 for cleaning. See Reinauer col. 3, ll. 62–67.
With this in mind, Raether-827 teaches a dust filter system 10 comprising a plurality of filter elements 32, with each filter element 32 being cleaned by pulses of compressed air that are channeled toward each filter element 32 by an accumulator 42 (the accumulator is therefore similar to the venturi 22 of Reinauer). See Raether-827 Fig. 2, [0021]. Each accumulator 42 has a length L1 running from top to bottom and an opening at the top and bottom (each opening is about the same size as opening 30 in tubesheet 28). Id. at Fig. 2. The relative size of the length L1 of the accumulator 42 to the diameter of each opening (at top and bottom) is result effective because pressure loss increases with increasing length L1, with length L1 being no longer than 3 times the length (diameter) of opening 30 and preferably about 25 to 75% of the diameter of the opening 30. Id. at [0027].
It would have been obvious to use routine experimentation to determine the optimal “passageway length” (length from bottom to top of the venturi 22) relative to the hydraulic diameter of the opening at the bottom of the venturi (roughly the size of the opening at the top) o reduce the pressure loss of the pulses of compressed air sent into the venturi 22 for cleaning. A person of ordinary skill in the art would have had a reasonable expectation of success in achieving the claimed feature of—the “passageway length measured along the pulse axis from the filter end opening to the tube sheet opening…is equal to or greater than the hydraulic diameter of the filter end opening of the pulse collector”—because Raether-827 teaches that the length of the entire accumulator 42 (including both the upper and lower halves) should be 25 to 300% of a diameter of the opening at either end of the accumulator 42. See MPEP 2144.05, subsection II (where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation).
Regarding claim 57, Reinauer teaches a filter bag retainer 20 (the “yoke”) extending into the dirty chamber 16 away from the aperture 23 in the tube sheet 12 along the vertical axis, as claimed. See Reinauer Fig. 2, col. 3, ll. 29–35.
Regarding claim 58, Reinauer teaches that the filter bag retainer 20 comprises two rods (“support beams”) aligned with the vertical axis that are arranged asymmetrically about the vertical axis, as claimed, as seen in the figure below.
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Regarding claim 63, Reinauer teaches that the venturi 22 (the “pulse collector”) is located in the dirty chamber 16, as claimed, as seen in Fig. 1.
Regarding claim 64, Reinauer teaches that the venturi 22 (the “pulse collector”) is located in the dirty chamber 16 with the top end of the venturi 22 (the “tube sheet end of the pulse collector”) located on a bottom side (“dirty side”) of the tube sheet 12, as seen in Fig. 1.
Claim 55 is rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Reinauer, US 4,270,935 in view of Green et al., US 2004/0079231 A1 in view of Suzuki et al., US 2009/0100827 A1 and in further view of Raether, US 5,562,746.
Regarding claim 55, Reinauer teaches that the “pulse section” (upper half of venturi 22) comprises opposing walls defining the passageway in the pulse section, as claimed, which are the side walls of the venturi 22 in the upper half, as seen in Fig. 1. The opposing walls diverge from the vertical axis (the “pulse axis”) at an included angle, as seen in Fig. 1.
Reinauer differs from claim 55 because it is silent as to the included angle that the side walls diverge. But Raether teaches a filter system that uses compressed air pulses that are directed into a venturi 70 for cleaning. The venturi 70 has an upper section with opposing walls that define a passageway through the venturi 70, where the opposing walls diverge from a vertical axis at an angle of divergence of 7.5°. See Raether-746, Fig. 8, col. 8, ll. 28–52. The angle of divergence is result effective because it is selected so that the air jet is focused into the interior of the upper section 72 of the venturi 70. Id.
It would have been obvious to use routine experimentation to determine the optimal angle that the opposing walls of the upper section of the venturi 22 of Reinauer as modified diverge from the pulse axis to optimize the focus of the compressed gas pulse directed into the upper section (“pulse section”) of the venturi 22. A person of ordinary skill in the art would have had a reasonable expectation of success in achieving the claimed range of the angel being less than or equal to 10 degrees, because Raether teaches an angel of 7.5°. See MPEP 2144.05, subsection II (where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation).
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Claims 59 and 60 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Reinauer, US 4,270,935 in view of Green et al., US 2004/0079231 A1 in view of Suzuki et al., US 2009/0100827 A1 and in further view of Klimczak et al., US 5,395,409.
Regarding claim 59, Reinauer teaches that the system comprises a filter bag 18 (the “filter element”) and is configured such that air passing into the interior of the venturi 22 (the “passageway of the pulse collector”) through the “filter end opening” (bottom of the venturi 22) passes through an interior volume of the filter bag 18 before reaching the bottom of the venturi 22, as claimed, because fluid flows through inlet 28 in the bottom of the housing 10, through the filter bag 18 and then into the bottom of the venturi 22. See Reinauer Figs. 1, 2, col. 3, ll. 16–56. The filter bag 18 comprises a “filter element opening” at a junction between the bottom end of the venturi 22 (the “filter end of the pulse collector”) and the filter bag 18, which is the interior opening of the filter bag 18 that surrounds the venturi 22. Id.
Reinauer differs from claim 59 because it is silent as to whether the filter bag 18 is attached to the bottom end of the venturi 22, as claimed.
But Klimczak teaches a dust collector comprising a filter bag 26 that is attached onto a cylindrical sleeve 30 inside of the filter bag 26 (similar to the venturi 22) using a band 34. See Klimczak Fig. 2, col. 3, ll. 46–57. The band 34 is beneficial because clamps the bag 26 onto the sleeve 30 providing a secure connection between the bag 26 and the sleeve 30. It would have been obvious to use the band 34 of Klimczak to attach the filter bag 18 of Reinauer to the bottom of the venturi 22 (the widest part of the venturi 22) to provide a secure connection between the filter bag 18 and the venturi 22.
Regarding claim 60, Reinauer teaches a filter bag retainer 20 (the “yoke”) extending into the dirty chamber 16 away from the aperture 23 in the tube sheet 12 along the vertical axis, as claimed. See Reinauer Fig. 2, col. 3, ll. 29–35. The filter bag retainer 20 comprises two rods (“support beams”) aligned with the vertical axis that are arranged asymmetrically about the vertical axis, as claimed, as seen in the figure below. The filter bag 18 comprises a wire mesh sleeve 38 (“alignment features”) arranged to align with the rods of retainer 20 when the filter element is in only one rotational orientation relative to the vertical axis (as the sleeve 38 goes over the rods). Id. at Fig. 2, col. 4, ll. 19–38.
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Claims 61 and 62 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Reinauer, US 4,270,935 in view of Green et al., US 2004/0079231 A1 in view of Suzuki et al., US 2009/0100827 A1 in view of Klimczak et al., US 5,395,409 and in further view of Forester et al., US 4,543,113.
Regarding claims 61 and 62, Reinauer teaches that the filter bag 18 comprises a “tubular filter media” (the media of the filter bag 18) defining an “interior surface” (the inside surface of the bag 18) facing an “interior volume of the filter element” (the inside of the bag 18) and an “exterior surface facing away from the interior volume” (the outside of the bag 18), as claimed. See Reinauer Figs. 1, 2, col. 3, ll. 16–29. The filter media of the bag 18 defines a “tubular filter media length” measured along a “tube axis” extending from the top end (“first end”) to bottom end “(second end”) of the tubular bag 18, as claimed. Id.
The filter bag 18 also comprises a “filter element housing comprising a first end cap” (claim 61), which is the structure at the top of the filter bag 18 attaching it to the tube sheet 12, as seen in Fig. 2. This structure (the “first end cap”) comprises an opening configured to allow access to the interior volume of the filter bag 18, as seen in Fig. 2 (claim 62).
Reinauer differs from claims 61 and 62 because it is silent as to a second end cap at the bottom end of the of the filter bag 18 with the second end cap being configured to prevent access to the interior of the filter bag 18, as claimed.
But Forester teaches a bag-like fabric filter assembly 40 comprising an open end cap (collar 72) at the upper end that attaches to a tube sheet, and a closed end cap 22 at the bottom end. The closed end cap 22 is beneficial because it seals the bottom of the filter bag 40 so that dirty gas will pass through the side of the filter bag, into the interior and out the top opening into a clean gas outlet compartment 50, as seen by the flow arrows in Fig. 1. See Forester Fig. 1, col. 7, l. 49–col. 8, l. 5.
It would have been obvious to provide a closed end cap at the bottom of the filter bag 18 in Reinauer to seal the bottom of the bag 18 so that gas flows through the sides of the bag 18 into the interior of the bag 18 through the venturi 22 and into the clean air chamber 14 in the manner described in the reference. See Reinauer col. 3, ll. 47–68.
Allowable Subject Matter
Claim 65 is 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.
Claim 65 is allowable over Reinauer in view of Green. It is noted that Green teaches a blowpipe nozzle 50 with a similar structure as the diverging pulse guide (e.g., 290) shown in the Applicant’s disclosure. See Green Fig. 3, [0029]; Spec. Fig. 8, p. 36, l. 29–p. 37, l. 6.
But the nozzle 50 of Green differs from the “pulse guide” of claim 65, at least because the nozzle 50 does not have opposing interior surfaces in a first section hat diverge from a longitudinal axis at a first angle greater than 0 degrees with the opposing surfaces in a second section diverging from the longitudinal axis at a second angle greater than the first angle. Instead, the nozzle 50 has a first, conical section that attaches to blowpipe 46 with opposing interior surfaces that do not diverge from the longitudinal axis (as this section is conical) with a second, tapered section with interior walls that diverge from the longitudinal axis at a constant angle. See Green Figs. 3, 6, [0029]. It is noted that the step seen in the “first section” of the nozzle 50 of Green could be considered a “first angle” of 90 degrees, which arguably reads on a “first angle that is greater than zero (0) degrees.” But, with this interpretation, the angle of the “second section” is less than 90 degrees (seen in Fig. 6)—and therefore this fails to read on the “second angle is greater than the first angle.”
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Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to T. BENNETT MCKENZIE whose telephone number is (571)270-5327. The examiner can normally be reached Mon-Thurs 7:30AM-6:00PM.
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T. BENNETT MCKENZIE
Primary Examiner
Art Unit 1776
/T. BENNETT MCKENZIE/Primary Examiner, Art Unit 1776
