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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on January 5, 2026 has been entered.
Response to Arguments
Applicant’s arguments, filed January 5, 2026, have been fully considered.
Applicant has argued that the claim objections and the rejection under 35 U.S.C. 112(a) set forth in the Office Action mailed October 3, 2025 have been overcome by amendment. Examiner agrees, and has withdrawn the previous objections and rejections.
Applicant has argued that examiner’s position that Ryobi can be optimized to have the claimed voltage, torque output, and weight is incorrect, because “this reasoning ignores the fundamental technical contradiction between Ryobi’s original design goal and the core technical features of claim 1.” “Ryobi is a ‘lightweight product’ designed for homeowners and DIYers, with original parameters of ‘40V battery voltage, 73.2 N-m output torque, and 18.2 kg weight.’ Its design goal focuses on lightweight usability for ordinary household tasks, not high torque (73.2 N-m is far below the 83 N-m requirement of Claim 1 and cannot be routinely optimized). In contrast, claim 1 achieves a balance between high torque and lightweight, which demands simultaneous satisfaction of three interrelated technical indicators,” i.e. voltage, torque, and weight (see Remarks, Bottom of Page 7 and top of Page 8, emphasis applicant’s).
Examiner respectfully disagrees. As an initial matter, 73.2 N-m is not far below 83 N-m (83 N-m is an increase of 13 percent over 73.2 N-m), and there is at least a small buffer between the 18.2 kg weight disclosed by Ryobi and the 20 kg limit imposed by the claim (20 kg is a 10 percent increase over 18.2 kg). In other words, an allowance exists for increasing the weight of Ryobi to increase performance, while remaining below 20 kg. Secondly, examiner disputes that there is a “fundamental technical contradiction between Ryobi’s original design goal” and the features of claim 1. Ryobi discloses a consumer tool for digging holes. A tool with higher output torque, and perhaps some added weight, does not fundamentally contradict this purpose. For example, a current search of homedepot.com and Lowes.com yields battery-powered augers ranging from 18 Volts and 2.2 kg tool weight (Ryobi product with unrated torque output) to 80 Volts and 80 N-m of torque at 16.6 kg of tool weight (GreenWorks product). These products are all marketed to consumers and have the same design goal of digging holes.
Applicant’s assertion that the optimization of high torque and lightweight “demands simultaneous satisfaction of three interrelated technical indicators” is correct. However, the interplay between these three indicators (voltage, output power, and weight) is taught explicitly in the prior art, and is relatively straightforward. The interplay is best summarized by Yamaoka, which states “increasing the voltage of the battery may increase the power supplied to the motor or the engine, and thus may increase the efficiency and performance of the power tool system. But a trade-off for increased power is increased weight…which may increase inconvenience, fatigue, and amount of work for the user to operate the power tool system” (paragraph 0004). Given that the interaction between these factors is well understood, optimizing them is within the level of ordinary skill in the art.
Applicant argues that “the examiner’s assertion that increasing voltage alone can boost torque while maintaining weight is technically unfounded. Ryobi’s lightweight design is based on a low-torque motor configuration and to increase torque to 83 N-m, a higher-power motor is required. A higher-power motor inherently requires a larger size and heavier weight—a technical constraint that cannot be resolved by simply increasing battery voltage” (Remarks, Page 8). Examiner acknowledges that increasing voltage alone may not satisfy the design constraint imposed by the need to keep weight in a manageable range. However, Examiner also asserts that one of ordinary skill is also “a person of ordinary creativity, not an automaton” (MPEP 2141 II. C.). Increasing voltage is not the only tool available to one of ordinary skill in modifying Ryobi. Weight-saving measures may be employed (e.g. using different materials or upgrading to a higher-performance outrunner motor as suggested by Hoffman) by one of ordinary skill during the optimization process. Importantly, the issue of added weight is known explicitly in the prior art. Thus, one of ordinary skill would not blindly increase the voltage of the tool without considering added weight. Yamaoka teaches one of ordinary skill to take weight into account and attempt to minimize the amount of weight added due to the increase in performance.
Regarding the Brotto reference:
Applicant has argued that “Brotto fails to teach or suggest that higher-voltage batteries generate larger motor output” (Remarks, Pages 8 and 9). Examiner respectfully disagrees. However, examiner has removed the Brotto reference from the rejection under 35 U.S.C. 103, as this reference is not necessary to make the point regarding the interplay between voltage, torque, and weight. Thus, applicant’s arguments regarding Brotto are moot.
Regarding the Yamaoka reference:
Applicant has argued that “because Yamaoka explicitly teaches that a ‘trade-off for increased power is increased weight’ (paragraph 0004), there is no evidence to provide the conclusion that a combination of Ryobi, Brotto, and Yamaoka can achieve a total weight of 20 kg or less as claimed” (Remarks, bottom of Page 9 to top of Page 10). Examiner respectfully disagrees. Yamaoka is brought in merely to teach that increased weight is a factor that must be considered and mitigated when adding performance. Yamaoka does not need to teach the specific weight value that is claimed. The references, in totality, teach that battery voltage, motor performance, and weight are all related result-effective variables. This teaching alone (without the need for disclosure of specific numerical values) is enough to render their optimization obvious (see MPEP 2144.04 II. B.).
Regarding the Hoffman reference:
Applicant argues that “Hoffman does not address whether Ryobi’s tool structure is compatible with an external rotor motor, or whether such a combination would cause the tool weight to exceed the claimed range of 14-20 kg” (Remarks, Page 10). Examiner admits that the Hoffman reference does not provide an exact blueprint for incorporating an external rotor motor into Ryobi. However, examiner again refers to the fact that a person of ordinary skill “is also a person of ordinary creativity, not an automaton,” and that they “will be able to fit the teachings of multiple patents together like pieces of a puzzle” (MPEP 2141 II. C.). All the issues to be considered in modifying Ryobi are explicitly taught in the prior art and are straightforward. Increasing battery voltage can increase motor performance but also add weight, and care should be taken as excess weight can lead to user fatigue (Yamaoka). Using an external rotor motor can increase power without increasing motor size (Hoffman). Balancing of these factors is within the level of ordinary skill in the art, given the teachings that the prior art provides.
Applicant argues that “Yamaoka and Hoffman...are directed towards gardening blowers” rather than handheld digging tools. “When the battery voltage of a gardening blower is increased, it is less affected by the reaction force from the ground. However, when the battery voltage of the claimed handheld digging tool is increased, it is significantly affected by the reaction force from the ice/soil surfaces, which exerts a substantial impact on the overall operation of the handheld digging tool. By directly extending Brotto, Yamaoka, and Hoffman’s teachings from general cordless tools or blower[s] to the specific field of handheld digging tools, the examiner disregards the technical differences between these scenarios. Brotto, Yamaoka and Hoffman do not provide targeted technical guidance for optimizing the voltage, torque, and weight of handheld digging tools” (Remarks, Page 11). Examiner respectfully disagrees. While Yamaoka and Hoffman are both related to blowers, the specific teachings relied upon by the examiner are of general applicability. Applicant has not provided a persuasive reason why the general statements that increased battery voltage leads to increased output power (Yamaoka) and that outrunner motors provide better performance for the same motor diameter (Hoffman) are not applicable to digging tools. Additionally, the “reaction force” issue that applicant discusses is applicable to both blowers and digging tools. Blowers cause a reaction force in the direction opposite to the direction of airflow, which must be countered by the user. This is basic physics governed by Newton’s Third Law of Motion and one of ordinary skill in the art would be well prepared to consider this issue when modifying Ryobi to have more power. Again, one of ordinary skill is “not an automaton.” One of ordinary skill, working from the Ryobi reference (which already teaches an “electronic safety brake” that engages when the auger binds to the ground), is able to bear in mind the issue of reaction forces from the ground when making any modifications that add power to the Ryobi device.
Claim Interpretation
Claim 1 requires that “a weight of the handheld digging tool is greater than or equal to 14kg and less than or equal to 20kg.” Claim 1 also states that the handheld digging tool comprises a “main body…comprising a support mechanism and a drive mechanism, the drive mechanism comprising a direct current (DC) motor,” and “a battery pack.” The handheld digging tool is “configured to be selectively connected to” drill rod mechanisms. Thus, the handheld digging tool is being interpreted to include the main body (including the support mechanism and motor) and the battery pack, but not the drill rod. Thus, the 14kg to 20kg includes the weight of the battery pack but not the weight of the drill rod.
Claim Objections
Claim 23 is objected to because of the following informalities: The phrase “greater than or equal to 90 mm and” should be deleted, as it is already present in 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.
Claim(s) 1, 2, 5, 10-14, 21, and 23-25 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ryobi 40V HP Model RY40710 8” Auger Review (hereinafter Ryobi) in view of Yamaoka et al. (US 2016/0345714, hereinafter Yamaoka), Hoffman et al. (US 2021/0033115, hereinafter Hoffman), and Shook et al. (US 2021/0111649, hereinafter Shook).
With regard to claim 1, Ryobi discloses a handheld digging tool (see annotated Fig. provided below), comprising:
a main body (see Fig. below), selectively couplable with a first drill rod mechanism with a first function and a second drill rod mechanism with a second function (Ryobi also teaches different size bits, i.e. 4, 6, and 8 inch drill rod mechanisms—see Fig. below), the main body comprising a support mechanism (see Fig. below) and a drive mechanism (electric motor) supported by the support mechanism, the drive mechanism comprising a direct current (DC) motor (motor runs off of 40V battery—note that batteries supply DC power), and configured to be selectively connected to one of the first drill rod mechanism and the second drill rod mechanism (pin mechanism allows connection to other drill rods) to drive the first drill rod mechanism or the second drill rod mechanism to work; and
a battery pack (40 Volt battery) for supplying power to the DC motor;
wherein a nominal voltage of the battery pack is (Ryobi teaches 40V),
the DC motor is a brushless DC motor (“40V HP 8-inch brushless auger” as seen in the figure below)
a weight of the handheld digging tool is greater than or equal to 14 kg and less than or equal to 20 kg (Ryobi teaches a weight of 40.2 lbs., or 18.2 kg. See Fig. below).
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Ryobi fails to teach that the nominal voltage of the battery pack is greater than 40V, and that a maximum output torque of the auger is greater than 83 N-m. Instead, Ryobi teaches a battery voltage of 40V and an output torque of 53.98 ft-lbs, or 73.2 N-m. It is noted that these values are relatively close to being within the claimed ranges. Ryobi also fails to disclose the brushless motor having an external rotor, where the outer diameter of the motor is 90 mm.
Yamaoka teaches that “increasing the voltage of the battery may increase the power supplied to the motor or the engine, and thus may increase the efficiency and performance of the power tool system. But a trade-off for increased power is increased weight” (paragraph 0004). Thus, Yamaoka teaches that, in the art of cordless power tools, battery voltage is a result-effective variable that has a known relationship to motor output power and tool weight.
Hoffman teaches a battery-powered handheld tool which utilizes a brushless DC motor in an “outrunner” configuration (i.e. an external rotor—see Paragraph 0076). Hoffman states that “outrunner type motors may be particularly advantageous due to their ability to provide relatively higher torque for a given motor diameter as compared to inrunner type motors” (Hoffman, Paragraph 0076).
Shook teaches that, in the art of cordless power tools, “an increase in the size of the motor results in more power output given that the battery pack can supply the motor with sufficiently high input power” (paragraph 0077). Shook also teaches that “to maximize the power output of a power tool, common sense of those skilled in the art dictates providing a larger motor as allowed by the size of the power tool housing…produces higher power output from the motor” (paragraph 0079). Thus, Shook teaches that motor size is a result-effective variable, and that the size of the power tool housing must also be considered.
Collectively, Yamaoka, Hoffman, and Shook teach that battery voltage, motor type, and motor size are all result-effective variables having known relationships to tool performance and tool weight.
It would have been considered obvious to one of ordinary skill in the art, before the effective filing date of the invention, to have modified Ryobi to increase the battery voltage from 40 Volts to between 40 Volts and 80 Volts in order to increase motor output torque from 73.2 N-m to 83 N-m, with a reasonable expectation of success given that Yamaoka teaches that increased battery voltage is a result-effective variable that increases motor output power. Furthermore, it would have been considered obvious to simultaneously modify Ryobi’s motor to be the external rotor motor of Hoffman, with a reasonable expectation of success given that Hoffman teaches that an outrunner motor can provide greater power than an inrunner motor of the same size. Additionally, it would have been considered obvious to modify Ryobi’s motor to have an outer diameter of greater than 90 mm, with a reasonable expectation of success, as Shook teaches that it is “common sense” to use a larger motor to increase power, with consideration of any design constraints. Finally, it would have been considered obvious to maintain the tool weight below 20 kg, with a reasonable expectation of success, as Yamaoka teaches that additional tool weight is undesirable, and the relationships between battery voltage, motor output, motor type, motor size, and tool weight are all explicitly discussed in the prior art and are straightforward, such that balancing them is a matter of routine optimization.
With regard to claim 2, Ryobi as modified by Yamaoka, Hoffman, and Shook, teaches a torque output of 83 N-m, but not 85 N-m. However, it would have been considered obvious to further modify Ryobi to have an output torque of 85 N-m, for the same reasons as discussed above with regard to claim 1’s recitation of 83 N-m.
With regard to claim 5, Ryobi’s baseline torque-to-weight ratio is 4.1 N-m/kg (before the modifications proposed above with respect to claim 1). Thus, it would have been obvious to maintain such a ratio in modifying the tool to have additional power, as power-to-weight ratio is a vital design consideration (see the Ryobi document, which discusses “impressive power” while the tool is “reasonably lightweight and capable of being used by one person”—these are characteristics which one of ordinary skill in the art would seek to maintain).
With regard to claim 10, Ryobi teaches that the DC motor comprises an electric motor shaft rotating about an electric motor axis (as this is an inherent property of a DC brushless electric motor), and the first drill rod mechanism rotates about a first axis to drill a hole (see annotated Fig. above, which shows the electric motor output shaft aligned with the drill rod axis).
With regard to claim 11, Ryobi teaches that the support mechanism comprises a first support portion and a handle frame (see annotated Fig. provided below), the first support portion is connected to the drive mechanism, the handle frame bends and extends at two sides of the first support portion (see Fig. below), a first accommodating space for accommodating an operator is formed on a first side of the handle frame (Fig. below), a side opposite to the first side is a second side of the handle frame, and the handle frame comprises a first handle and a second handle which extend from the first side to the second side (see Fig. below).
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With regard to claim 12, Ryobi teaches that the battery pack is disposed on the drive mechanism and located on the first side of the handle frame (see Fig. above).
With regard to claims 13 and 25, Ryobi teaches that the first handle and the second handle extend from the first side to the second side to approach each other and along a direction perpendicular to the first axis, an included angle a between a projection of the first handle and a front and rear direction is greater than 0° and less than or equal to 30° or 15° (Ryobi at least teaches that an arbitrary tangent line along the curved portion of the handle forms an angle between 0 and 15 degrees –see Fig. above. Note that the claim does not contain a detailed definition of what “a projection” of the first handle is).
With regard to claim 14, Ryobi teaches that the first handle and the second handle are disposed symmetrically about a first plane, and the first axis is in the first plane (this is visible in Ryobi’s Figures).
With regard to claims 21 and 24, it would have been considered obvious to have modified Ryobi in view of Yamaoka, Hoffman, and Shook such that the motor has an outer diameter greater than or equal to 100 mm, with a reasonable expectation of success, as Shook teaches that it is “common sense” to use a larger motor to increase power, with consideration of any design constraints.
With regard to claim 23, given that Ryobi has already been modified to have a motor diameter of 90 mm, the limitation of “less than or equal to 105 mm is already met.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ryobi in view of Yamaoka, Hoffman, and Shook as applied to claim 1 above, and further in view of Qiao (US 2020/0251696).
With regard to claim 4, Ryobi, as modified by Yamaoka, Hoffman, and Shook, fails to teach the specific voltage of 56 V.
Qiao teaches that known voltages for cordless power tool batteries are “18 V, 20 V, 28 V, 36 V, 38 V, 40 V, 42 V, 56 V or 60 V” (Paragraph 0201).
It would have been considered obvious to one of ordinary skill in the art, before the effective filing date of the invention, to have modified Ryobi in view of Yamaoka, Hoffman, and Shook such that the battery voltage was 56 V, with a reasonable expectation of success, given that Qiao teaches that 56 V battery packs are known to be used within the art of consumer cordless power tools.
Claim(s) 7-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ryobi in view of Yamaoka, Hoffman, and Shook as applied to claim 1 above, and further in view of Chung et al. (US 2023/0358101, hereinafter Chung).
With regard to claim 7, Ryobi in view of Yamaoka, Hoffman, and Shook fails to disclose that the drive mechanism further comprises a transmission assembly disposed on a side of the DC motor facing the first drill rod mechanism.
Chung discloses a battery powered auger that has a transmission assembly (60) on a side of a DC motor (50) that faces a drill rod mechanism (12).
It would have been considered obvious to one of ordinary skill in the art, before the effective filing date of the invention, to have modified Ryobi in view of Yamaoka, Hoffman, and Shook to have the gear reducing transmission assembly of Chung, in order to increase the mechanical advantage of the motor and provide greater output torque.
With regard to claim 8, Ryobi as modified by Yamaoka, Hoffman, Shook, and Chung discloses that the transmission is a gear reduction assembly (given that Chung teaches that “the gearbox 60 is configured to be driven by the motor 50 with a gear reduction ratio”).
With regard to claim 9, Ryobi teaches that the drive mechanism has a first output rotational speed adapted for the first function and a second output rotational speed adapted for the second function (the Fig. below shows a Hi and Low speed for the motor. These speeds could be used for the first function and the second function. Note: the claim only requires two speeds. The intended use of the speeds, i.e. for the first or the second function, is given little patentable weight).
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Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ryobi in view of Yamaoka, Hoffman, and Shook as applied to claim 11 above, and further in view of Foster et al. (US 2022/0007571, hereinafter Foster).
With regard to claim 15, Ryobi in view of Yamaoka, Hoffman, and Shook teaches that either the first handle or the second handle is provided with a trigger switch (trigger shown in Ryobi Fig. provided above, adjacent “Hi” and “Low” speed indicator).
Ryobi in view of Yamaoka, Hoffman, and Shook fails to teach that a stroke of the trigger switch is controlled so that a pulse-width modulation (PWM) signal of the DC motor is controlled. Ryobi gives few details regarding the setup of the trigger control, forcing one of ordinary skill to look elsewhere regarding how to construct the trigger system.
Foster teaches that it is typical for DC brushless motors to utilize pulse width modulation for control (paragraph 0054).
It would have been considered obvious to one of ordinary skill in the art, before the effective filing date of the invention, to have modified Ryobi in view of Yamaoka, Hoffman, and Shook to utilize pulse width modulation for control of the motor, with a reasonable expectation of success given that Foster teaches the use of pulse width modulation to control a brushless DC motor of a battery powered garden tool.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ROBERT E FULLER whose telephone number is (571)272-6300. The examiner can normally be reached M-F 8:30AM - 5:30PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Tara Schimpf can be reached at 571-270-7741. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ROBERT E FULLER/ Primary Examiner, Art Unit 3676