DETAILED ACTION
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 .
Drawings
Figure 11b should be designated by a legend such as --Prior Art-- because only that which is old is illustrated. See MPEP § 608.02(g). Corrected drawings in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. The replacement sheet(s) should be labeled “Replacement Sheet” in the page header (as per 37 CFR 1.84(c)) so as not to obstruct any portion of the drawing figures. 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
Claims 1 – 18 are objected to because of the following informalities:
Claim 1, line 3: “comprising” should read --comprising:--.
Claim 1, line 6: “the profile of the teeth” should read --a profile of the plurality of teeth--.
Claim 4, lines 3-4: “at a right angle the opposite lateral faces of the toothed wheel” should read --at a right angle with respect to the opposite lateral faces of the toothed wheel--.
Claim 5, line 2: “the axial component of the force” should read --an axial component of a force--.
Claim 6, line 2: “the profile of the teeth” should read --the profile of the plurality of teeth--.
Claim 7, line 2: “the helix contact ratio parameter” should read --a helix contact ratio parameter--.
Claim 8, line 2: “the profile of the teeth” should read --the profile of the plurality of teeth--.
Claim 10, line 1: “the lower involute truncation diameter” should read --a lower involute truncation diameter of the two truncation diameters--.
Claim 10, lines 2-3: “with Φp pitch diameter” should read --with Φp being a pitch diameter--.
Claim 11, line 1: “the upper involute truncation diameter” should read --an upper involute truncation diameter of the two truncation diameters--.
Claim 11, line 3: “with Φp pitch diameter” should read --with Φp being a pitch diameter--.
Claim 14, line 1: “An apparatus according to claim 13” should read --The apparatus according to claim 13--.
Claim 17, line 2: “with Φp pitch diameter” should read --with Φp being a pitch diameter--.
Claim 18, line 2: “with Φp pitch diameter” should read --with Φp being a pitch diameter--.
Claims 2 – 18 are objected to for being dependent on claim 1.
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 – 9 and 13 – 16 are rejected under 35 U.S.C. 103 as being unpatentable over Rossi, Manuele (US 2018/0023561 – herein after Rossi) in view of Langer, Gerd (US 2008/0056927 – herein after Langer).
In reference to claim 1, Rossi teaches a bi-helical toothed wheel (1, see figs. 3-4) for hydraulic gear apparatuses (see ¶54), configured to be bound to a support shaft (5) to form a driving or driven wheel of said hydraulic apparatus (see ¶60) and comprising:
a plurality of teeth (6/6’) extending with variable helix angle with a continuous function in the longitudinal or axial direction of the tooth (see abstract),
wherein each tooth (see fig. 4) has a central zone (zone B) with variable helix angle (see abstract) wherein a helix transition from right-handed to left-handed occurs (see ¶29);
wherein a profile of the plurality of teeth keeps a shape continuity in each cross section thereof (see abstract),
wherein each tooth comprises at least an initial (zone A) and a terminal zone (zone C).
Rossi remains silent on the bi-helical toothed wheel, wherein each of the initial and terminal zone has variable helix angle, at the two opposite lateral ends of the toothed wheel, wherein in these initial and terminal zones the helix angle decreases when approaching the lateral end of the toothed wheel.
However, Langer teaches a pump, wherein (see ¶18) the acute-angled edges of the rotors (or toothed wheel(s)) are reduced to 90° angles for reducing wear in the edge’s region, thus minimizing pressure losses and increasing the serviceable life. In helical geometry, a 90° intersection with the lateral face occurs when the helix angle decreases to 0° as it approaches the end (this is further evident from applicant’s own submitted figures in the instant application in figs. 30a-30b, wherein fig. 30a shows the edge at acute angle while fig. 30b shows the edge with angle 90°).
Langer is pertinent to the specific problem addressed by the applicant: preventing wear and structural failure at the acute terminal ends of helical pump rotors. Thus, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to provide both the initial and terminal zones with variable helix angle to each tooth in the pump of Rossi using the teaching of Langer for the purpose of reducing wear in the edge’s region, thus minimizing pressure losses and increasing the serviceable life of the toothed wheel, as recognized by Langer above.
In reference to claim 2, Rossi, as modified, teaches the bi-helical toothed wheel, wherein each tooth (see ¶29) further comprises a proximal intermediate zone (zone A; of Rossi) and a distal intermediate zone (zone C; of Rossi) with constant helix angle (see Rossi’s abstract) which connect the initial and terminal zones (provided as per teaching of Langer) to the central zone (zone B; of Rossi) [note that in view of the modification discussed above in claim 1; the initial and terminal zones are the ones with variable helix angle provided using the teaching of Langer; thus, in claim 2, zone A and zone C of Rossi are claimed “proximal intermediate zone” and “distal intermediate zone”].
In reference to claim 3, Rossi, as modified, teaches the bi-helical toothed wheel, wherein the initial and terminal zones (provided as per teaching of Langer) and the central zone (of Rossi) with variable helix angle are directly connected by inflection points (inherent feature in view of the proposed modification discussed above in claim 1).
In reference to claim 4, Rossi, as modified, teaches the bi-helical toothed wheel, wherein the helix angle is null at the opposite lateral ends of the toothed wheel, that is the profile of each single tooth joins at a right angle with respect to the opposite lateral faces of the toothed wheel [in view of Langer’s fig. 4 and disclosure in ¶18: the acute-angled edges of the rotors/wheels are reduced to 90° angles; thus, the claimed feature is inherently present in the modified Rossi’s toothed wheel; in the modified toothed wheel, the lateral ends are “straight” and “parallel with the longitudinal axis of the wheel”; a path parallel to the longitudinal axis represents a null helix angle (0°)].
In reference to claim 5, Rossi, as modified, teaches the bi-helical toothed wheel, wherein an axial component of a force exchanged by said wheel meshed during use with another identical wheel is null at the lateral ends [as discussed above in claim 4: path parallel to the longitudinal axis of the wheel represents a null helix angle (0°), which inherently results in a null axial force component in the modified Rossi’s toothed wheel].
In reference to claim 6, Rossi, as modified, teaches the bi-helical toothed wheel, wherein the profile of the plurality of teeth is mirrored with respect to a centre plane passing through the transition point between right-handed and left-handed helix [see ¶29 and fig. 4 of Rossi].
In reference to claim 7, Rossi, as modified, teaches the bi-helical toothed wheel, wherein the helix contact ratio parameter is comprised between 0.6 and 1 [see Rossi’s claim 11: “with contact ratio between 0.6 and 1.4”].
In reference to claim 8, Rossi, as modified, teaches the bi-helical toothed wheel, wherein the profile of the plurality of teeth of the toothed wheel is a non-encapsulating profile [see disclosure in Rossi’s abstract].
In reference to claim 9, Rossi, as modified, teaches the bi-helical toothed wheel, wherein the non-encapsulating profile is defined by [see Rossi’s fig. 13 and ¶119] two arcs of circumference or elliptical crest (segment A) and bottom portions (segment C) connected by an involute profile (segment B) comprised between two truncation diameters (first truncation diameter = circle that passes through point labeled “UP” in fig. A below; second truncation diameter = circle that passes through point labeled “LP” in fig. A below; these truncation diameters are similarly present as shown by applicant as “Φetr” and “Φitr” in their own fig. 6).
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Fig. A: Edited fig. 13 of Rossi to show claim interpretation.
In reference to claim 13, Rossi, as modified, teaches a hydraulic gear apparatus comprising a pair of toothed wheels according to claim 1 [see Rossi’s claim 11].
In reference to claim 14, Rossi, as modified, teaches the apparatus, wherein said apparatus is a volumetric pump or a hydraulic gear motor [see Rossi’s claim 14].
In reference to claim 15, Rossi, as modified, teaches the bi-helical toothed wheel, wherein the helix contact ratio parameter is comprised between 0.6 and 0.8 [see Rossi’s claim 11: “with contact ratio between 0.6 and 1.4”].
In reference to claim 16, Rossi, as modified, teaches the bi-helical toothed wheel, wherein the helix contact ratio parameter is equal to 0.65 [see Rossi’s claim 11: “with contact ratio between 0.6 and 1.4”].
Claims 10, 11, 17 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Rossi in view of Langer and Williams, Logan (US 2020/0124047 – herein after Williams).
Regarding claims 10 and 17,
Rossi teaches the bi-helical toothed wheel, wherein a lower involute truncation diameter (diameter corresponding to circle that passes through point labeled “LP” in fig. A above) of the two truncation diameters is selected equal to: Φitr = Φp - Φp * p1, with Φp being a pitch diameter and the parameter p1 [the claimed equation is merely a mathematical expression that define the physical location of the claimed truncation diameters where these geometric segments transition; because Rossi teaches the same “non-encapsulating” profile, this mathematical relationship is inherently present], as in claim 10.
Rossi remains silent on the bi-helical toothed wheel, wherein the parameter p1 comprised between 9.7% and 9.9%, as in claim 10; and wherein the parameter p1 is equal to 9.8%, as in claim 17.
However, Williams evidences a similar non-encapsulating profile for gear tooth, wherein he states the hybrid curve must be “continuously differentiable” (smooth) at the points where the curves meet (see ¶68 or claim 15) and teaches using a “numerical algorithm” to calculate these parameters and minimize error (see ¶69).
Thus, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to arrive at the specific parameter p1 to be between 9.7% and 9.9% or is equal to 9.8% in the Rossi’s toothed wheel because Williams explicitly teaches that the truncation points (B and C, wherein point C corresponds to claimed lower involute truncation diameter) are determined through numerical solving algorithms. These algorithms are used to ensure the profile is continuously differentiable and provides a full sweep of the tooth space. The claimed specific percentages represent nothing more than the predictable result of routing optimization for the particular gear size being modeled. Since Williams provides the motivation to optimize these points (see Williams ¶21) to maintain a ‘smooth contact during gear mesh’, the selection of these specific value is a matter of standard engineering design. Further, applicant places no criticality on the claimed specific percentages for parameter p1 as evident from use of phrase “preferably” (see page 6, lines 14-16 or page 14, line 5 in filed specification).
Regarding claims 11 and 18,
Rossi teaches the bi-helical toothed wheel, wherein an upper involute truncation diameter (diameter corresponding to circle that passes through point labeled “UP” in fig. A above) of the two truncation diameters is selected equal to: Φetr = Φp + Φp * p2, with Φp being a pitch diameter and the parameter p2 [the claimed equation is merely a mathematical expression that define the physical location of the claimed truncation diameters where these geometric segments transition; because Rossi teaches the same “non-encapsulating” profile, this mathematical relationship is inherently present], as in claim 11.
Rossi remains silent on the bi-helical toothed wheel, wherein the parameter p2 comprised between 12.1% and 12.3%, as in claim 11; and wherein the parameter p2 is equal to 12.2%, as in claim 18.
However, Williams evidences a similar non-encapsulating profile for gear tooth, wherein he states the hybrid curve must be “continuously differentiable” (smooth) at the points where the curves meet (see ¶68 or claim 15) and teaches using a “numerical algorithm” to calculate these parameters and minimize error (see ¶69).
Thus, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to arrive at the specific parameter p2 to be between 12.1% and 12.3% or is equal to 12.2% in the Rossi’s toothed wheel because Williams explicitly teaches that the truncation points (B and C, wherein point B corresponds to claimed upper involute truncation diameter) are determined through numerical solving algorithms. These algorithms are used to ensure the profile is continuously differentiable and provides a full sweep of the tooth space. The claimed specific percentages represent nothing more than the predictable result of routing optimization for the particular gear size being modeled. Since Williams provides the motivation to optimize these points (see Williams ¶21) to maintain a ‘smooth contact during gear mesh’, the selection of these specific value is a matter of standard engineering design. Further, applicant places no criticality on the claimed specific percentages for parameter p2 as evident from use of phrase “preferably” (see page 6, lines 17-19 or page 14, line 8 in filed specification).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Rossi in view of Langer and Rossi et al. (WO 2021/019014A1 – herein after Rossi II).
Rossi remains silent on the bi-helical toothed wheel, wherein the top of each tooth has a cutting edge, defined by a limited thickness projecting with respect to the profile.
However, Rossi II teaches the gear wheel, wherein (see fig. 3 and abstract) the top of each tooth (11) has a cutting edge (12), defined by a limited thickness projecting with respect to the profile.
Thus, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to provide the top of each tooth in the bi-helical toothed wheel of Rossi with a cutting edge as taught by Rossi II for the purpose of “removing material from the pump body by removing chips during the running-in phase, so as to limit or even avoid the plastic deformation of the pump body which occurs in the known solutions”, as recognized by Rossi II (see page 4, lines 10-15).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Pan et al. (CN 115111156A) teaches a pump with herringbone gear (see figs. 6-7) having initial and terminal zones (in view of fig. 7: initial zone = one of the left/right zone or portion with lateral end; terminal zone = another of right/left zone or portion with lateral end) with decreasing variable helix angle.
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/CHIRAG JARIWALA/Examiner, Art Unit 3746
/ESSAMA OMGBA/Supervisory Patent Examiner, Art Unit 3746
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