Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s arguments, see page 6, filed April 6th, 2026, with respect to the rejection(s) of claim(s) 1 and 20 under 35 U.S.C. 102 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Thut (US 4786230).
Examiner agrees with Applicants arguments that Thut (20060180962) fails to teach the rotation of the rock guard with the impeller as currently claimed. Therefore, the rejection under 35 U.S.C. 102 has been withdrawn. However, a new grounds of rejection has been made under 35 U.S.C. 102 in view of Thut (US 4786230) below.
Drawings
The drawings are objected to because it is unclear what some reference characters are referencing due to the drawings consisting of grayscale backgrounds, particularly Figure 1. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Objections
Claim 7 is objected to because of the following informalities:
Claim 7 recites “the top portion”. However, the specification and figures refer to a “rock guard” rather than a “top portion” (see paragraph 0030 for example). Examiner recommends correcting “top portion” to “rock guard” to maintain consistency between the claims and the specification.
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 (i.e., changing from AIA to pre-AIA ) 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.
Claims 1, 4, 7-8, 10-12, and 14-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Thut (US 4786230).
Regarding Claim 1, Thut discloses an impeller for use in a molten metal pump, the impeller comprising: (a) a body including a plurality of blades or passages (Fig. 1 #46 – upper volute impeller with body and passages #79) and (b) a rock guard having an inverted cup-shape (Fig. 1 #45 – lower volute impeller as rock guard) wherein a top wall includes a bore configured to receive a shaft (Col. 8, lines 54-61; Fig. 1 – bore with shaft #7), a sidewall includes a plurality of openings (Figs. 1,6 #79 – ends of passageways as openings), and a rim mated to the body (Fig. 3 – top edge of #45 in contact with #76 as rim mated to body), such that rotation of the shaft results in rotation of the body and the rock guard (Col. 8, lines 59-63).
Regarding Claim 4, Thut discloses all the limitations of Claim 1 above. Thut further discloses wherein the sidewall of the rock guard has a height at least 50% of a height of the body (Fig. 1).
Regarding Claim 7, Thut discloses all the limitations of Claim 1 above. Thut further discloses wherein the at least part of the top portion is configured to extend above a pumping chamber of the molten metal pump Fig. 1 – lower impeller #45 as top portion extends above bottom of bore #60 as pumping chamber).
Regarding Claim 8, Thut discloses all the limitations of Claim 1 above. Thut further discloses wherein the sidewall is inwardly inclined between the rim and the top wall (Fig. 1).
Regarding Claim 10, Thut discloses all the limitations of Claim 1 above. Thut further discloses wherein the body includes a bearing ring (Fig. 1; see below).
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Regarding Claim 11, Thut discloses all the limitations of Claim 1 above. Thut further discloses wherein the openings are oval (Fig. 1).
Regarding Claim 12, Thut discloses all the limitations of Claim 1 above. Thut further discloses wherein the passages have at least one dimension that is smaller than an inlet to a space between adjacent blades or an inlet to the passages (Figs. 1,6).
Regarding Claim 14, Thut discloses all the limitations of Claim 1 above. Thut further discloses wherein the body includes an aperture receiving the shaft (Fig. 1).
Regarding Claim 15, Thut discloses all the limitations of Claim 1 above. Thut further discloses wherein a circumference of the top wall is less than a circumference of the rim (Fig. 1).
Regarding Claim 16, Thut discloses all the limitations of Claim 1 above. Thut further discloses wherein an interface between the top wall and the sidewall is rounded or beveled (Fig. 1).
Regarding Claim 17, Thut discloses all the limitations of Claim 1 above. Thut further discloses A molten metal pump including the impeller of claim 1 (abstract).
Regarding Claim 18, Thut discloses all the limitations of Claim 17 above. Thut further discloses a superstructure on which a motor is supported (Fig. 1 #2 - motor), a pump base including a pump chamber in which the impeller is received (Fig. 1 #30 – base with chamber), and a plurality of support posts connecting the superstructure to the pump base (Figs. 1,2 #9a,9b).
Regarding Claim 19, Thut discloses all the limitations of Claim 18 above. Thut further discloses wherein the plurality of openings reside above a top surface of the pump base (Figs. 4,6 – see below).
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Regarding Claim 20, Thut discloses a molten metal pump comprising a base defining a pumping chamber (Fig. 1 #30 – base with chamber), said base including an upper surface and a lower surface (Fig. 1; see below), at least one post engaging the base (Figs. 1,2 #9a,9b), and a shaft configured to drive an impeller (Fig. 1 #7 – shaft drives upper volute impeller #46), said impeller being disposed in the pumping chamber (Fig. 1), the impeller comprising a body including a plurality of blades or passages and a rock guard (Figs. 1,6 79 – passages with #45 – lower volute impeller as rock guard), the rock guard being attached to the body such that rotation of the shaft results in rotation of the rock guard and the body (Col. 8, lines 59-63), the rock guard including a top wall including a bore configured to receive the shaft and a sidewall including a plurality of openings (Figs. 1,6 #79 – ends of passageways as openings), the sidewall being inwardly inclined between the body and the top wall (Fig. 1), and wherein at least a portion of the sidewall extends above the upper surface of the base (Fig. 1; see below).
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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.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Thut.
Regarding Claim 9, Thut teaches all the limitations of Claim 8 above. However, Thut fails to teach wherein the incline is between about 20 and 50 degrees relative to a plane in which the rim resides.
Thut does teach that the incline is between 0 and 90 degrees relative to a plane in which the rim resides, the rock guard shaped to increase centrifugal pressure (Col. 9, lines 30-41; Fig. 1).
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close (See MPEP 2144.05 I.). It would have been obvious to a person of ordinary skill in the art that the incline of Thut could be between about 20 and 50 degrees relative to a plane in which the rim resides, as Thut teaches that an incline of more than 0 degrees and less than 90 degrees increases centrifugal pressure (Col. 9, lines 30-41), and claimed ranges overlapping ranges taught by the prior art are obvious (MPEP 2144. 05 I).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Thut in view of Thut, hereafter Thut ‘313 (US 20020146313).
Regarding Claim 13, Thut teaches all the limitations of Claim 1 above. However, Thut fails to teach wherein the bore includes at least one key- way configured to receive a key to secure the top portion to the shaft.
Thut ‘313 teaches an impeller with a bore including a key-way configured to receive a key to secure the impeller to the shaft (paragraph 0033). Thut and Thut ‘313 are analogous prior art as they each relate to molten metal pumps. Therefore, it would have been obvious to a person of ordinary skill in the art that the bore taught by Thut could include at least one key-way as taught by Thut ‘313, in order to secure the top portion to the shaft (Thut ‘313 paragraph 0033).
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Thut in view of Talbert et al., hereafter Talbert (US 4188172).
Regarding Claim 21, Thut teaches all the limitations of Claim 20 above. Thut further teaches wherein the openings are elongated in a direction parallel to an axis of the shaft (Fig. 1).
However, Thut fails to teach wherein the openings include forward and trailing walls canted in a direction of impeller rotation.
Talbert teaches a motel metal pump where openings are canted in the direction of the fluid flow path in order to more precisely direct the fluid (Col. 3, lines 47-52). Thut and Talbert are analogous prior art as they each relate to molten metal pumps. Therefore, it would have been obvious to a person of ordinary skill in the art that the openings taught by Thut could include forward and trailing walls canted in the direction of the impeller rotation, in order to more precisely direct the fluid (Talbert Col. 3, lines 47-52).
Allowable Subject Matter
Claims 2-3 and 5 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.
Regarding Claim 2, Thut teaches all the limitations of Claim 1 above. However, Thut fails to teach wherein the rock guard is comprised of material harder than the body.
Thut teaches that the rock guard and body are identical impellers and therefore have identical materials. None of the known prior art, alone or in combination, solves this deficiency. Therefore, the combination of features would be allowable.
Regarding Claim 3, Thut teaches all the limitations of Claim 1 above. Thut further discloses wherein the rock guard is comprised of a ceramic and the body is comprised of graphite, and the rock guard is cemented to the body.
Thut teaches that the rock guard and body are identical impellers and therefore have identical materials In addition, the rock guard and body are not cemented to each other. None of the known prior art, alone or in combination, solves this deficiency. Therefore, the combination of features would be allowable.
Regarding Claim 5, Thut teaches all the limitations of Claim 1 above. However, Thut fails to teach wherein the rim is cemented to a peripheral edge of the body.
Thut teaches that the rock guard and impeller are individually threaded onto the shaft and then rotate together. It would not be obvious to one of ordinary skill in the art, nor does any of the known prior art motivation one to cement the rim and body together. Therefore, the combination of features would be allowable.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Dyck (US 20240133381) teaches a pump with canted openings.
Tetkoskie (US 20130224038) teaches a molten metal pump.
Sweeney (US 3291473) teaches a molten metal pump with a rock guard.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JACKSON GILLENWATERS whose telephone number is (469)295-9151. The examiner can normally be reached 10:00AM-6:00PM ET, M-F.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, NATHANIEL WIEHE can be reached at (571) 272-8648. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JACKSON N GILLENWATERS/Examiner, Art Unit 3745
/NATHANIEL E WIEHE/Supervisory Patent Examiner, Art Unit 3745
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