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 .
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 (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 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(s) 1-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lawenius et al (US 11,225,922) in view of Honzawa et al (US 2015/0184595).
Regarding claims 1 and 7-8, Lawenius discloses a device and method of restricting a rotational speed of a crankshaft of an internal combustion engine of a handheld power tool (Col. 1, Lns. 14-18), the internal combustion engine comprising: the crankshaft 105, a cylinder 120, a piston 130 arranged in the cylinder and being connected to the crankshaft 105 (Fig. 1, shown), an ignition device (not shown, Col. 4, Lns. 58-59), configured to ignite an air/fuel mixture in the cylinder, an air inlet system for conducting air to the cylinder, a throttle valve arranged in the air inlet system (Fig. 1, shown intake system on the right side), and an electric actuator arrangement configured to move the throttle valve 150 between an open position and a closed position (Col. 6, Lns. 44-50, the throttle being an electrically actuated one), wherein the throttle valve is configured to restrict flow of air through the air inlet system when positioned in the closed position (Fig. 1, shown throttle), and wherein the method comprises the steps of,
when the rotational speed of the crankshaft reaches above an upper threshold speed: controlling the electric actuator arrangement to move the throttle valve towards the closed position (¶ [0139], above a threshold 407 the system controls the electric actuator to close a throttle valve to limit speed of the engine).
Lawenius fails to disclose retarding an ignition timing of the ignition device from an initial ignition timing to a retarded ignition timing. While Lawenius for its part discloses monitoring ignition timing (¶ [0137]), it does not contemplate modifying it.
Honzawa discloses an engine for a work tool which monitors and controls engine rotation speed (Abstract), wherein the control comprises detecting when an engine speed has exceeded a threshold value (¶ [0069]), and when it does initiating ignition control to retard the ignition timing to reduce engine output (¶ [0070] to [0074]), wherein a throttle opening is also controlled according to the engine speed (¶ [0073]), wherein this system allows for an effective and easy to apply system on various work tools to prevent overspeed (¶ [0007]).
It would have been obvious to one of ordinary skill in the art before the filing date of the invention to modify the handheld power tool engine control systems of Lawenius with the ignition timing controls of Honzawa because it would have allowed for an additional engine control to lower output when engine speeds exceed a threshold.
Regarding claim 2, the modified Lawenius discloses the method according to claim 1, wherein the step of retarding the ignition timing of the ignition device comprises the step of: maintaining a control of the ignition timing of ignition device to a retarded ignition timing when the rotational speed of the crankshaft is above the upper threshold speed (as modified by Honzawa in ¶ [0070], the ignition timing is modified until the speed drops sufficiently and then is returned to normal).
Regarding claim 3, the modified Lawenius discloses the method according to claim 1, wherein the step of retarding the ignition timing of the ignition device comprises the step of: controlling the ignition timing of ignition device such that the ignition timing is retarded with increasing rotational speeds above the upper threshold speed (as per Honzawa ¶ [0070], the ignition speed is retarded above a threshold and as per Lawenius, Col. 11, Lns. 25-35, the system is checking multiple thresholds).
Regarding claim 4, the modified Lawenius discloses the method according to claim 1, wherein the step of retarding the ignition timing of the ignition device comprises the step of: controlling the ignition timing of the ignition device such that the ignition timing is advanced with decreasing rotational speeds above the upper threshold speed (as per Honzawa ¶ [0070] and Lawenius, Col. 11, Lns. 25-35, there are different thresholds of unwanted speeds for increasing throttle and ignition timing modifications).
Regarding claim 5, the modified Lawenius discloses the method according to claim 1, wherein the method comprises the step of: advancing the ignition timing to the initial ignition timing when the rotational speed of the crankshaft declines below the upper threshold speed (as per Honzawa ¶ [0070],the ignition timing returns to an advanced amount on lower speeds).
Regarding claim 6, the modified Lawenius discloses the method according to claim 1, wherein the method comprises the step of: controlling the electric actuator arrangement to move the throttle valve to the open position when the rotational speed of the crankshaft declined below the upper threshold speed (as per Honzawa ¶ [0070],the ignition timing returns to an advanced amount on lower speeds and it would have been obvious to also return the throttle valve to its initial (open) state).
Regarding claim 9, the modified Lawenius discloses the handheld power tool according to claim 8, wherein the electric actuator arrangement comprises an electric motor (Lawenius, Col. 9, Lns. 26-28).
Regarding claims 10-13, the modified Lawenius discloses the handheld power tool according to claim 9, but fails to disclose wherein the electric motor is a stepper motor with an output shaft connected to the throttle valve via the transmission, wherein the transmission provides a positive gear ratio between the output shaft of the electric motor and the throttle valve, and wherein the transmission comprises a planetary gear set.
However, examiner takes official notice that it would have been sufficiently old and well-known in the art before the filing date of the invention such that one of ordinary skill in the art would have found it obvious to make use of a stepper motor for the electric motor of the modified Lawenius’ throttle valve because it would have allowed for a high precise and controllable electric motor for use with a valve. And further wherein, the inclusion of a planetary gearbox transmission for inclusion with the stepper motor is sufficiently old and well-known in the art before the filing date of the invention such that one of ordinary skill in the art would have found it obvious to make use of a planetary gear transmission device because it allows for improved resolution of the valve modification as well as a significant reduction in positional error.
Regarding claim 14, the modified Lawenius discloses the handheld power tool according claim 8, wherein the internal combustion engine comprises a crankcase at least partially enclosing the crankshaft, and wherein the air inlet system comprises an air inlet duct connected to the crankcase, and wherein the throttle valve is arranged in the air inlet duct (Fig. 1 of Lawenius, shown engine having an inlet duct connected to the engine and the crankcase 110).
Regarding claim 15, the modified Lawenius discloses the handheld power tool according to claim 8, wherein the internal combustion engine is a crankcase scavenged two-stroke internal combustion engine, and wherein the air inlet system is configured to conduct air to the cylinder at least partially via a crankcase of the internal combustion engine (¶ [0002] of Lawenius, the engine being a scavenged two-stroke engine).
Regarding claim 16, the modified Lawenius discloses the handheld power tool according to claim 8, wherein the internal combustion engine comprises a main throttle valve arranged in the air inlet system, wherein the handheld power tool comprises a first handle and a throttle actuator arranged at the first handle, and wherein the throttle actuator is operably connected to the main throttle valve.
Regarding claim 17, the modified Lawenius discloses the handheld power tool according to claim 16, wherein the throttle actuator is operably connected to the main throttle valve via a mechanical connection (Lawenius discloses the system being for handheld power tools in ¶ [0002], with Honzawa showing gin Fig. 1A – 1B a typical power tool with handles and a throttle control 17 on the handles).
Regarding claim 18, the modified Lawenius discloses the handheld power tool according to claim 8, wherein the internal combustion engine comprises an exhaust system configured to conduct exhaust gas from the cylinder to the surroundings (inherent of internal combustion engines), but fails to disclose wherein the exhaust system comprises a catalytic converter.
Examiner takes official notice that it would have been sufficiently old and well-known in the art before the filing date of the invention such that one of ordinary skill in the art would have found it obvious to make use of a catalytic converter in the exhaust path since they are known in the art to reduce unwanted emissions.
Regarding claim 19, the modified Lawenius discloses the handheld power tool according to claim 8, wherein the handheld power tool is a chainsaw or a power cutter (¶ [0003] of Honzawa).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KEVIN A LATHERS whose telephone number is (571)272-1050. The examiner can normally be reached M-F 10a-6p.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Lindsay Low can be reached at 5712721196. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/KEVIN A LATHERS/Primary Examiner, Art Unit 3747
