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 .
DETAILED ACTION
Response to Amendment
Per the Request for Continued Examination filed 11 May 2026, the Amendment filed 4 May 2026 has been entered. Claims 1-11, 22-27, and 29-31 are pending. Applicant's amendments have overcome each and every objection previously set forth in the Final Office Action mailed 4 March 2026.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the each of the horizontal and vertical planes recited in the claims must be shown or the feature(s) canceled from the claim(s), including the following planes:
“a first horizontal plane” and “a second horizontal plane” as recited in claims 1 and 23;
“a first vertical plane” and “a second vertical plane” as recited in each of claims 23 and 31; and
“a third horizontal plane” as recited in claim 25.
No new matter should be entered.
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.
Specification
The specification is objected to as failing to provide proper antecedent basis for the claimed subject matter. In mechanical cases, the meaning of every term used in any of the claims should be identified in the descriptive portion of the specification by reference to the drawing, designating the part or parts therein to which the term applies. See 37 CFR 1.75(d)(1) and MPEP § 608.01(o). Correction of the following is required:
the terms “a first horizontal plane” and “a second horizontal plane” as recited in claims 1 and 23 should be used in the specification by reference to the drawings;
the terms “a first vertical plane” and “a second vertical plane” as recited in each of claims 23 and 31 should be used in the specification by reference to the drawings; and
the term “a third horizontal plane” as recited in claim 25 should be used in the specification by reference to the drawings.
The examiner suggests adding each of the above planes to at least one of the figures in the drawings, and providing each of the planes with a reference character included in the specification.
Claim Objections
The claims are objected to because of the following informalities:
Claim 23 at line 3 recites, “the shoe, a top side and a bottom side”. This recitation should read – the shoe, the shoe including a top side and a bottom side – to make clear that the top side and bottom side are sides of the shoe (rather than, as one example, of the circular saw).
Claim 24 at lines 2-3 recites, “and includes a user engaging end portion”. This recitation should read – and the first arm includes a user engaging end portion – to make clear that “and includes a user engaging end portion” is describing the first arm, rather than the lever.
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.
Claim(s) 1-4, 10, 22-23, 25, and 31 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP S62-162003 to Seiji in view of GB 2339404 A to Robert Bosch GmbH (hereinafter ‘Bosch’).
Regarding claim 1, Seiji discloses a circular saw (see in particular the embodiment of Figs. 1-3; note that all page number references to the English language translation of Seiji are not relative to the page numbers printed in the English translation, but are instead based on a count of pages, since not all pages of the English translation are numbered) comprising:
a shoe 3 that includes a top side and a bottom side (see Figs. 1 and 2), the bottom side is opposite the top side and is configured to engage a workpiece 11 (see Fig. 1 showing the bottom side of the shoe 3 in engagement with the workpiece 11);
a blade 2 that extends in an upward direction from the top side of the shoe 3 and a downward direction from the bottom side of the shoe 3 (see Figs. 1 and 2);
an upper blade housing 4;
a lower blade guard 6 coupled to the upper blade housing 4 (see Figs. 1 and 3) and that rotates about an axis (a same axis as that about which the blade 2 rotates; compare Figs. 1 and 3 and see also the first paragraph of the eighth page of the English language translation of Seiji) between a closed position (see Fig. 1) and an open position (see Fig. 3, although the open position can optionally be opened further from Fig. 3) and includes a guide track 6a, and
a lever 9 having a user engaging end (an upper end of the lever 9 relative to Fig. 3 – see the direction arrow ‘D’ in which a user pulls the first lever 9) and an additional lever 8 having a guide track engaging end (a lower end of the additional lever 8 relative to Fig. 1 – the guide track engaging end being the end of the lever 8 engaging the guide track 6a as can be seen by comparing Figs. 1 and 2), the lever 9 coupled to the upper blade housing 4 at a lever pivot point positioned between the guide track engaging end and the user engaging end (see the annotated Fig. 1 below; pivoting of the first lever 9 is evident in comparison of Figs. 1 and 3), wherein the guide track engaging end is moveably coupled to the guide track 6a to rotate the lower blade guard 6 by pulling up on and moving along a length of the guide track 6a (see Figs. 1 and 3, with Fig. 3 showing the guide track engaging end moved along the guide track 6a and the rotation of the second lever 8 resulting in a pulling up movement on the guide track 6a);
wherein, when the lower blade guard 6 is in the closed position, the guide track engaging end intersects a first horizontal plane and the guide track intersects a second horizontal plane that is spaced in the downward direction from the first horizontal plane (see the annotated Fig. 1 below), wherein the first horizontal plane and the second horizontal plane are parallel to the bottom side of the shoe (see annotated Fig. 1 below).
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Regarding claim 2, Seiji discloses that the user engaging end (i.e., the upper end of the lever 9) is positioned exterior to the upper blade housing 4 (see Figs. 1-3).
Regarding claim 3, Seiji discloses that the guide track engaging end applies an outward force to the guide track 6a (see Fig. 1, where the direction of the force applied to the guide track 6a by the guide track engaging end is orthogonal to the guide track 6a, where is an ‘outward’ direction due to being away from the lower blade guard 6, such that the force is ‘outward’ with respect to at least the lower blade guard 6).
Regarding claim 4, Seiji discloses that the guide track engaging end engages the guide track 6a at a trailing horizontal side of the axis (i.e., a left side of the axis relative to Fig. 1) opposite a cutting horizontal size of the axis (i.e., a right side of the axis relative to Fig. 1).
Regarding claim 10, Seiji discloses a lower guard spring 7 that is positioned between the upper blade housing 4 and the lower blade guard 6 adjacent to the axis (see Figs. 1 and 3, noting that the spring 7 extends from the upper blade housing 4 to the lower blade guard 6, with the left end of the spring 7 attached to the upper blade housing 4 and the right end of the spring attached to the lower blade guard 6).
Regarding claim 22, Seiji discloses that the guide track 6a projects from an inner side wall of the lower blade guard 6 (see Fig. 2, where the guide track 6a projects from a leftward from a left, or inner, wall of the blade guard 6) and is located in an interior portion of the lower blade guard 6 that is spaced from an outer periphery of the lower blade guard 6 (see Fig. 2, where the outer periphery of the lower blade guard 6 is at a bottom of the blade guard 6; see also Fig. 1).
Regarding claim 23, Seiji discloses a circular saw (see in particular the embodiment of Figs. 1-3) comprising:
a shoe 3 that includes a longitudinal axis that extends from a front end of the shoe 3 to a rear end of the shoe 3 (see Fig. 1, where a longitudinal axis extends in a right-to-left direction along the plane of the page from the right, front end of the shoe 3 to the left, rear end of the shoe 3), a top side and a bottom side (see Figs. 1 and 2; top and bottom sides of the shoe 3, respectively), the bottom side is opposite the top side and is configured to engage a workpiece 11 (see Fig. 1 showing the bottom side of the shoe 3 in engagement with the workpiece 11);
an output spindle (located at a center of blade 2; see Fig. 1 and the final paragraph of page 6 of the English translation of Seiji) that rotates about a rotational axis that is perpendicular to the longitudinal axis of the shoe 3 (see the annotated Fig. 1 above, where the rotational axis extends out of the page, where is perpendicular to the plane of the page along which the longitudinal axis extends);
a blade 2 that is coupled to the output spindle (see Fig. 1 and the final paragraph of page 6 of the English translation of Seiji) and extends in an upward direction from the top side of the shoe 3 and a downward direction from the bottom side of the shoe 3 (see Figs. 1 and 2);
an upper blade housing 4;
a lower blade guard 6 rotatably coupled to the upper blade housing 4 (see Figs. 1 and 3; see also the first paragraph of the eighth page of the English language translation of Seiji), the lower blade guard 6 including a guide track 6a (see Figs. 1-3) formed on an inner side wall of the lower blade guard 6 (see Fig. 2); and
a lever 9 coupled to the upper blade housing 4 at a lever pivot point (see the annotated Fig. 1 above);
another lever 8 including a guide track engaging end (a bottom of the lever 8 relative to Fig. 1) that engages and moves along the guide track 6a to move the lower blade guard 6 between a closed position (see Fig. 1) and an open position (see Fig. 3, although the open position can optionally be opened further from Fig. 3);
wherein the guide track engaging end intersects a second vertical plane that is located between the output spindle and the rear end of the shoe 3 (see the annotated Fig. 1 above), wherein the second vertical plane is perpendicular to the bottom side of the shoe 3 (see the annotated Fig. 1 above);
wherein, when the lower blade guard 6 is in the closed position, the guide track engaging end intersects a first horizontal plane and the guide track intersects a second horizontal plane that is spaced in the downward direction from the first horizontal plane (see the annotated Fig. 1 below; even if Fig. 1 does not illustrate the blade guard 6 in the fully closed position, further closing movement of the blade guard 6 will only move the second horizontal plane lower), wherein the first horizontal plane and the second horizontal plane are parallel to the bottom side of the shoe (see annotated Fig. 1 below).
Regarding claim 25, Seiji discloses that when the lower blade guard 6 is in the closed position (see Fig. 1), the guide track engaging end is located between the shoe 3 and a third horizontal plane that is parallel to the bottom side of the shoe 3 and that extends through the rotational axis of the output spindle (see the annotated Fig. 1 above; while no ‘third horizontal plane’ is illustrate, a third plane through the rotational axis is above the guide track engaging end, and the shoe 3 is below the guide track engaging end, thus satisfying claim 25).
Regarding claim 31, Seiji discloses that the guide track engaging end intersects a second vertical plane that is located between a rotational axis of the blade 2 and a rear end of the shoe 3 (see the annotated Fig. 1 above), where the second vertical plane is perpendicular to the bottom side of the shoe 3 (see the annotated Fig. 1 above).
Seiji discloses two levers that collectively have the guide track engaging end and the user engaging end, rather than a single lever that has both the guide track engaging end and the user engaging end. Thus, Seiji fails to disclose that the lever that has the user engaging end also has the guide track engaging end as required by claim 1. Seiji also fails to disclose that the lever includes a second arm that extends from the lever pivot point, that the second arm includes the guide track engaging end, and the lever pivot point intersects a first vertical plane that is located between the output spindle and the front end of the shoe, wherein the first vertical plane is perpendicular to the bottom side of the shoe, as required by claim 23. Seiji fails to disclose that the lever pivot point intersects a first vertical plane that is located between the rotation axis of the blade and a front end of the shoe, where the first vertical plane is perpendicular to the bottom side of the shoe, as required by claim 31.
Like Seiji, Bosch also teaches a circular saw having a lever that a user can actuated to manually move a lower blade guard from a closed position to an open position. Unlike Seiji, though, Bosch relies on a single lever to move the lower blade guard. Turning to claimed features, Bosch teaches a lever 26 that has a user engaging end (see the end to which force 37 is applied in Fig. 3) and a guide track engaging end (an end of the lever 26 with ball 34 in Fig. 3). [Claim 1] Bosch also teaches that the lever includes a second arm 24 that extends from a lever pivot point 27, the second arm includes the guide track engaging end (see the end of the lever 26 with the ball 24 in Fig. 3), and the lever pivot point 27 intersects a first vertical plane that is located between an output spindle 10 and a front end of a shoe 18 (in Fig. 3, the lever pivot point is to the right of the axis 16 of the spindle 10 and is to the left of stop 21, such that the first vertical plane is located at approximately the location shown in the annotated Fig. 2 below), wherein the first vertical plane is perpendicular to a bottom side of the shoe 18 (see the annotated Fig. 2 below). [Claim 23, also relevant to claim 31]
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It is apparent to one of ordinary skill in the art, being a mechanical engineer or one with similar training and having experience in linkage configurations, that the lever configuration of Seiji is problematic. As shown in the annotated Fig. 1 of Seiji below, during opening of the lower blade guard, a pulling force exerted onto the lever 9 is nearly in alignment with a direction between the pivots of the lever 8. As a result, only a small component of the pulling force on the lever 9 produces rotation of the lever 8 at the configuration of the lower blade guard shown in Fig. 1 of Seiji, and thus a large initial pulling force is required to be exerted on the lever 9 to initiate opening of the lower blade guard. Also as a result, the lever of Seiji is susceptible to jamming – e.g., if a user pulls the lever 9 at a slight angle relative to a longitudinal axis of the lever 9, such that the pulling direction exerted on the lever 9 aligns with the alignment direction of the pivots of the lever 8, then the pulling force exerted on the lever 9 does not produce any rotation of the lever 8. This situation is illustrated by the direction of the arrow acting on the lever 9 in the annotated Fig. 1 of Seiji below. Upon pulling the lever 9 in the direction in indicated in the annotated Fig. below, the lever 8 is not rotated despite the pulling force exerted on the lever 9, leading to no rotation of the lower blade guard. Thus, the lever configuration of Seiji is problematic both because only a small component of the force exerted on the lever 9 is in a direction required to produce rotation of the lower blade guard and because the levers of Seiji are susceptible to jamming when the lever 9 is pulled at even a slight angle.
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Therefore, it would have been obvious to one of ordinary skill in the art to replace the levers 8 and 9 of Seiji with a single lever having a lever pivot point located between the output spindle and the front end of the shoe as taught by Bosch. This modification is advantageous because it reduces the amount of force required to initiate opening of the lower blade guard, which is a concern of Bosch (see the first paragraph of page 7 of Bosch). As illustrated in the annotated Fig. 3 of Bosch below, the force 37 exerted to the user engaging end of the lever 26 produces a nearly opposite direction force on the guide track engaging end of the lever 26 (the force on the guide track engaging end is tangential relative to rotation about the lever pivot point 27). Thus, the force acting on the guide track engaging end of the lever of Bosch is closely aligned with the force direction required to initiate opening of the lower blade guard. As such, a far greater percentage of the initial opening force applied to the user engaging end of the lever of Bosch is transmitted into rotation of the lower blade guard than is the case with the lever configuration of Seiji. Moreover, the lever configuration of Bosch is not susceptible to jamming as is the lever configuration of Seiji. As result, replacing the two levers of Seiji with a single lever pivoted at the location of Bosch is advantageous to reduce the amount of force required to initiate opening of the lower blade guard, as well as to remove a risk of jamming of the lower blade guard. Finally, this modification includes providing Seiji with a single lever that engages the guide track in the manner disclosed by Seiji, such that Seiji’s user engaging end and guide track engaging end are provided at opposite ends of a single lever. This modification does not include providing Seiji with a flexible pulling means.
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Claim(s) 5-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP S62-162003 to Seiji in view of GB 2339404 A to Bosch as applied to claim 1 above, and further in view of GB 2339404 A to Bosch and GB 2600961 A to Donson et al.
Regarding claims 5 and 6, Seiji, as modified, discloses that the lower blade guard is configured such that an average rotation per thumb force applied to the user engaging end of the lever to achieve a full retraction of the lower blade guard is some undisclosed value over a full course of retraction of the lower blade guard (regarding of the exact magnitude of force required by the lower blade guard of Seiji, as modified, the force does have some average value over the full rotation of the lower blade guard since various magnitudes of force are applied over the full rotation, and these various magnitudes necessarily have some average value).
Regarding claim 7, Seiji, as modified, discloses that the lower blade guard is configured to rotate through a range of motion by applying force to the user engaging end of the lever with a difference of some undisclosed value between a highest minimum force and a lowest minimum force needed to rotate the lower blade guard (a ‘highest minimum force’ and ‘lower minimum force’ refer to forces at various rotational positions of the blade guard, where at each rotational position of the blade guard there is some respective ‘minimum force’ that will produce further rotation of the blade guard for that particular rotational position of the blade guard, hence the ability for there to be multiple ‘minimum forces’; as disclosed by Seiji, as modified, each position of the blade guard has some minimum force that is required to be applied to the lever to overcome forces such as friction and resistance from spring 7 of Seiji to produce additional rotational movement of the blade guard).
Seiji, as modified, fails to explicitly disclose the particular magnitude of thumb force required to operate the lever to open the lower blade guard. As a result, Seiji, as modified, fails to explicitly disclose that the average rotation per thumb force is at least 1.8 degrees per Newton over the full course of retraction as required by claim 5; that the average rotation per thumb force is at least 3.5 degrees per Newton over the course of the full course of retraction as required by claim 6; and that the difference between the highest minimum force and the lowest minimum force is no more than 20 newtons as required by claim 7.
Bosch, however, teaches that the magnitude of thumb force applied to a lever 26 to open a lower blade guard is selected to be a low value that increases only moderately through the range of rotation of the lower blade guard 15 in order to provide safe and ergonomically optimized swiveling of the guard (see page 2 at the first partial paragraph). Further, Damon teaches configuring a lever 52 whose actuation opens a lower blade guard 36 so that the lever provides a mechanical advantage so that the user’s leverage and control are improved (see page 13, lines 5-8). Damon also teaches that a shape of a guide track on the lower blade guard 36 can be selected to achieve different degrees angular rotation profiles (see page 13, lines 24-31) – the angular rotation profile determines an amount of force required for each degree of rotation of the lower blade guard (e.g., if a small amount of lever movement is required to produce a large rotation of the lower blade guard, the input force to the lever is greater than if a large degree of lever movement is required to produce a small rotation of the lower blade guard).
Therefore, since it is known in the art to be desirable to select a magnitude of force applied to a lever to open a lower blade guard to be low value that increases only moderately through a range of rotation of the lower blade guard in order to provide a safe and ergonomic optimized swiveling of the lower blade guard, since it is known in the art to configure a lever whose actuation opens a lower blade guard to provide a mechanical advantage so that the user’s leverage and control are improved, and finally since it is known in the art to select a ramp profile of a guide track of a lower blade guard to achieve a desired angular rotation profile of the lower blade guard, it would have been an obvious matter of design choice to a person of ordinary skill in the art to select the average rotation per thumb force to be at least 3.5 degrees per Newton over the full course of retraction, and to select the difference between the highest and lowest minimum forces to be no more than 20 Newtons, because discovering an optimum thumb force at each pivot location of the lower guard would have been a mere design consideration based on ensuring safe and ergonomic swiveling of the guard. Such a modification would have involved only routine skill in the art to accommodate the aforementioned requirement(s), especially in view of the fact that Bosch provides a motivation to one of ordinary skill in the art to provide a low rotational force, and in view of the fact that Damon teaches configuring a lever to provide a mechanical advantage and also configuring a ramp profile of a guide track on a lower blade guard to achieve a desired rotation profile. It has been held that discovering an optimum value of a result effective variable (here, the result effective variable being a force required to pivot the lower blade guard at each point of rotation of the guard, which also determines the difference in minimum and maximum force) involves only routine skill in the art. One of ordinary skill in the art, being a mechanical engineer, is able to optimize a lever system to reduce the amount of force required to pivot the lower blade guard.
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP S62-162003 to Seiji in view of GB 2339404 A to Bosch as applied to claim 1 above, and further in view of GB 2600961 A to Donson et al.
Seiji, as modified, fails to disclose that the lever includes a roller wheel coupled to the guide track engaging end that rolls along the guide track as required by claim 8.
Donson teaches a lever 52 that includes a roller wheel 64 coupled to a guide track engaging end of the lever 52 (a lower, left end of the lever 52 relative to Fig. 10) that rolls along a guide track 70 (see Fig. 10).
Therefore, it would have been obvious to one of ordinary skill in the art to provide the guide track engaging end of the lever of Seiji, as modified, with a roller wheel that rolls along the guide track in view of the teachings of Donson. This modification is advantageous because it reduces friction in the movement of the lower blade guard, reducing the amount of force that a user must provide and also providing a smoother lower blade guard movement action. Alternatively, this modification is obvious under KSR Rationale B – simple substitution of one known, equivalent element for another to obtain predictable results. Seiji, as modified, differs from the claimed device by substitution of a roller wheel in place of the guide track contacting element of the lever of Seiji. Donson teaches a roller wheel that applies a force to a guide track of a lower blade guard of a circular saw to move the lower blade guard to an open position. One of ordinary skill in the art could have substituted the roller wheel of Donson for the element at the guide track engaging end of the lever of Seiji, as modified, because both structures perform the exact same function of moving along a guide track to produce rotation of a lower blade guard (even if the roller wheel of Donson does so with less friction).
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP S62-162003 to Seiji in view of GB 2339404 A to Bosch as applied to claim 1 above, and further in view of US Pat. No. 11,364,652 B2 to Kani et al.
Seiji, as modified, fails to disclose a lever spring positioned between the upper blade housing and the lever pivot point, the lever spring biased to restore the lever to a resting position as required by claim 9.
Kani teaches that a lever spring 95 is positioned between an upper blade housing 50 and a lever pivot point 70a (see Fig. 6; the lever spring 95 is positioned between, e.g., wall 51 of the housing 50 shown in Fig. 3 and the lever pivot point 70a measured in vertical direction parallel to the plane of the page, i.e., measured in a direction parallel to the plane of the saw blade), the lever spring 95 biased to restore a lever 90 to a resting position (see Fig. 2 and 6 and col. 6, lines 30-34). Kani teaches that the lever spring is advantageous to urge the lever back to an initial position when the lever is no longer operated (see col. 6, lines 35-41).
Therefore, it would have been obvious to one of ordinary skill in the art to provide Seiji, as modified, with a lever spring as taught by Kani in order to aid in returning the lever to an initial position when no force is applied to the lever.
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP S62-162003 to Seiji in view of GB 2339404 A to Bosch as applied to claim 1 above, and further in view of GB 2339404 A to Bosch.
Seiji, as modified, fails to disclose that the lever includes an aperture positioned at the lever pivot point, and the lever is coupled to the upper blade housing via a bushing positioned in the aperture as required by claim 11. (Note that the modification of Seiji in view of Bosch discussed above with respect to claim 1 does not contemplate any particular manner of attaching the lever.)
Bosch, at the embodiment of Figs. 7-8, discloses that the lever 26’ includes an aperture positioned at a lever pivot point 27 (see Figs. 7-8), and the lever 26’ is coupled to an upper blade housing 13 via a bushing 401 positioned in the aperture (see Figs. 7 and 8). Bosch teaches that the bushing is advantageous because the bushing allows the lever to rotate freely while being axially restrained (see Bosch at the final sentence of page 7 though the first sentence of page 8).
It would have been obvious to one of ordinary skill in the art to provide the lever of Seiji, as modified, with an aperture at the lever pivot point, and to couple the lever the upper blade housing via a bushing positioned in the aperture, in view of the teachings of Bosch. This modification is advantageous because it provides a connection for the lever at the lever pivot point that allows the lever to rotate freely (which in turn is advantageous to reduce the amount of force a user must apply to the lever to move the lower blade guard, since frictional resistance to lever pivoting is reduced) and also because it restrains the lever in the axial direction (which reduces ‘slop’ in the lever and a results in a higher-quality feel to the circular saw). This modification is further obvious under KSR Rationale A – combining prior art elements according to known methods to yield predictable results. Seiji, as modified, and Bosch, taken together, teach each element required by claim 11. One of ordinary skill in the art could have combined the elements as claimed by known methods, in particular by pivotally coupling the lever of Seiji, as modified, to the upper blade housing using the method of Bosch. In combination, each element performs the same function as it did separate – Seiji, as modified, already discloses a lever pivotally coupled to an upper blade housing, where rotation of the lever drives motion of a lower blade guard, and Bosch teaches a particular structure for pivotally coupling a lever to an upper blade housing where rotation of the lever also drives motion of a lower blade guard. One of ordinary skill in the art would have recognized that the results of this combination were predictable because the function of the lever of Seiji, as modified, is not modified in any way, and instead this modification merely provides some particular pivotal coupling between the lever and upper blade housing.
Claim(s) 24 and 29 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP S62-162003 to Seiji as modified by GB 2339404 A to Bosch as applied to claim 23 above, and further in view of GB 2600961 A to Donson et al.
Regarding claim 24, Seiji, as modified, discloses that the lever includes a first arm that extends from the pivot point (see first arm 23 of Bosch in Fig. 3, which arm is provided to Seiji in the modification of claim 23 above) and includes a user engaging end portion exterior to the upper blade housing (see Bosch at Figs. 2 and 3); and the second arm (see second arm 24 of Bosch in Fig. 3, which arm is provided to Seiji in the modification of claim 23 above).
Regarding claim 29, Seiji, as modified, discloses that the lever pivot point is located between the guide track engaging end and the user engaging end portion (this feature is evident from Fig. 3 of Bosch, where the lever pivot point 27 is located between the guide track engaging end at ball 34 and the user engaging end portion receiving force 37), and the guide track engaging end portion moves away from the output spindle when moving the lower blade guard from the closed position to the open position (this feature is evident from a comparison of Figs. 1 and 3 of Seiji – the guide track engaging end portion moves radially away from the output spindle as the lower blade guard opens; see also Fig. 3 of Bosch, where as lever 26 rotates, the guide track engaging end portion having ball 34 moves away from the spindle 10).
Seiji, as modified, fails to disclose that the second arm includes a curved portion that extends around the output spindle as required by claim 24. Note, however, as is evident from Fig. 3 of Bosch, the second arm of the lever of Seiji (i.e., the end of the lever rearward of the pivot point) extends across the output spindle when extending from the pivot point to the guide track engaging portion of the lever.
Donson teaches a circular saw having a lever 52 for moving a lower blade guard 36. Donson teaches that when providing the lever 52 to engages a guide track 68 on the lower blade guard 36, where the lever 52 has a user engaging end 60 forward of an output spindle 28 and a guide track engaging portion 64 rearward of the output spindle 28 (see Figs. 9 and 10), the lever 52 includes a curved portion that extends around the output spindle 28 (see Figs. 9 and 10). As can be seen in Figs. 9 and 10 of Donson, providing the lever with the curved portion allows the lever to extend around, and thus not interfere with, the hub of the lower blade guard and the output spindle.
Therefore, in view of the second arm of the lever of Seiji, as modified, extending from the pivot point to the guide track engaging portion, it would have been obvious to one of ordinary skill in the art to provide the second arm of Seiji, as modified, with a curved portion that extends around the output spindle in view of the teachings of Donson. This modification is advantageous to allow the lever to extend from a front end of the circular saw toward a rear end of the circular saw so that the pivot point can be positioned in front of the output spindle with the guide track engaging portion being rearward of the output spindle, without the lever interfering with the output spindle or the hub of the lower blade guard as the lever extends across the output spindle and hub. Moreover, this modification is merely a change in the shape of the lever, and a change in form or shape is generally recognized as being within the level of ordinary skill in the art, absent any showing of unexpected results. In re Dailey et al., 149 USPQ 47. Since Donson teaches a lever that is curved to extend around an output shaft, there is presently no showing of unexpected results.
Claim(s) 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP S62-162003 to Seiji as modified by GB 2339404 A to Bosch as applied to claim 23 above, and further in view of GB 2600961 A to Donson et al.
Seiji, as modified, fails to disclose that the guide track engaging end includes a roller that rolls along the guide track as required by claim 26.
Donson teaches a lever 52 whose guide tracking engaging end includes a roller 64 that rolls along a guide track 70 (see Fig. 10).
Therefore, it would have been obvious to one of ordinary skill in the art to provide the guide track engaging end of the lever of Seiji with a roller that rolls along the guide track in view of the teachings of Donson. This modification is advantageous because it reduces friction in the movement of the lower blade guard, reducing the amount of force that a user must provide and also providing a smoother lower blade guard movement action. Alternatively, this modification is obvious under KSR Rationale B – simple substitution of one known, equivalent element for another to obtain predictable results. Seiji, as modified, differs from the claimed device by substitution of a roller wheel in place of the guide track contacting element of the lever of Seiji, as modified. Donson teaches a roller wheel that applies a force to a guide track of a lower blade guard of a circular saw to move the lower blade guard to an open position. One of ordinary skill in the art could have substituted the roller wheel of Donson for the element at the guide track engaging end of the lever of Seiji, as modified, because both structures perform the exact same function of moving along a guide track to produce rotation of a lower blade guard (even if the roller wheel of Donson does so with less friction).
Claim(s) 27 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP S62-162003 to Seiji as modified by GB 2339404 A to Bosch as applied to claim 23 above, and further in view of US Pub. No. 2017/0136652 A1 to Mortaro et al., as evidenced by GB 2600961 A to Donson.
Regarding claim 27, Seiji, as modified, discloses that the guide track 6a includes a linear portion (see Fig. 1 of Seiji), wherein the guide track engaging end moves along the linear portion when the lower blade guard 6 is moved between the closed position and the open position (compare Figs. 1 and 3 of Seiji).
Seiji, as modified, discloses a linear guide track 6a (see Fig. 1 of Seiji). As such, Seiji, as modified, fails to disclose that the portion of the guide track along which the guide track engaging end moves when the blade guard is moved is curved as required by claim 27.
Mortaro, though, teaches a guide track 344 that includes a curved portion (see the annotated Fig. 4 below, where the curved portion is indicated as a ‘first portion’), wherein a guide track engaging end 340 of a lever 324 moves along the curved portion when a lower blade guard 308 is moved between open and closed positions (see Fig. 4 and paragraph 31). [Claim 27] Moreover, it is known in the art that the shape of a guide track can be selected by a designer to achieve a desired angular rotation profile to the movable lower guard in response to a rotation of the lever (see Donson at page 13, lines 24-31).
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Therefore, it would have been obvious to one of ordinary skill in the art to provide the guide track of Seiji, as modified, with a curved portion, wherein the guide track engaging portion moves along the curved portion when the lower blade guard is moved between the open and closed positions in view of the teachings of Mortaro. This modification is obvious because the shape of the guide track is known to be a result effective variable, where a designer can select a guide track shape in order to achieve a desired angular rotation profile of the lower blade guard. It is known in the art that the shape of the guide track determines the amount of movement of the lever required for some desired amount of rotation of the lower blade guard. Since a person of ordinary skill in the art is a mechanical engineer, and since a mechanical engineer has training to select cam configurations that produce a designed rotational response from a lever rotational input, one of ordinary skill in the art is able to select a guide track shape, inclusive of a curved shape as taught by Mortaro, to achieve a desired relationship between lever rotation and lower blade guard rotation. There is a tradeoff between a small amount of lever rotation produce a large amount of lower blade guard rotation (in which case the force applied to the lever is relatively high, but a movement amount of the lever is relatively low) with a large amount of lever rotation being required to produce the same amount of lower blade guard rotation (in which case the force input is relatively low, but the amount of movement of the lever is higher). One of ordinary skill in the art can balance the ergonomic considerations of lever ‘throw’ magnitude vs lever input force to select a desired cam profile for the guide track.
Claim(s) 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP S62-162003 to Seiji as modified by GB 2339404 A to Bosch as applied to claim 23 above, and further in view of US Pub. No. 2017/0136652 A1 to Mortaro et al.
Seiji, as modified, fails to disclose that when the lower blade guard is in the closed position, at least a portion of the guide track is spaced in the downward direction from the bottom side of the shoe as required by claim 30 (Seiji is not explicit in discussing any amount that the lower blade guard may continue to rotate counterclockwise relative to Fig. 1 – however, if the lower blade guard were to rotate sufficiently far counterclockwise relative to Fig. 1 to cover the entire blade 2 in the closed position, then the guide track 6a would extend below the bottom side of the shoe 3 in comparison of the angular amount of rotation of the blade guard 6 required for the blade guard 6 to cover the blade 2 and the amount of rotation of the blade guard 6 for the guide track 6a to be below the bottom side of the shoe 3).
Mortaro teaches a lower blade guard 308 that pivots to a fully closed position in which an entirety of a lower edge of a blade 124 is covered (see Fig. 5 of Mortaro – no cutting edge portion of the blade 124 is exposed). Mortaro teaches that when the lower blade guard 308 is in the closed position, at least a portion of a guide track 344 is spaced in a downward direction from a remainder of a saw body 304 (see Fig. 5).
Therefore, it would have been obvious to one of ordinary skill in the art to configure the guide track of Seiji, as modified, so that a portion of the guide track extends in the downward direction from the bottom side of the shoe when the lower blade guard is in the closed position. First, as taught by Mortaro, a lower blade guard can be pivotable to cover an entirety of a lower cutting edge of the blade, which enhances safety because the no portion of the cutting edge of the blade is exposed when the lower blade guard is in the closed position, such that the possibility of contact with the cutting edge of the blade is eliminated. It would have been obvious to one of ordinary skill in the art to configure the lower blade guard of Seiji, as modified, to rotate further closed relative to Fig. 1 of Seiji such that the entirety of the cutting edge of the blade is covered in view of the teachings of Mortaro. This modification enhances safety because no portion of the cutting edge is exposed when the lower blade guard is in the covered position. As is evident from Fig. 1 of Seiji, rotating the lower blade guard further counterclockwise such that the lower blade guard covers the entire lower cutting edge of the blade results in the guide track being below the bottom side of the shoe – the amount of rotation of the lower blade guard required to cover the cutting edge of the blade is greater than the amount of rotation of the lower blade guard required for the guide track to be partially below the bottom side of the shoe.
Response to Arguments
Applicant's arguments filed 4 May 2026 have been fully considered but they are not persuasive. The Applicant argues that Seiji fails to disclose the arrangement of the first and second horizontal planes now required by claims 1 and 23. This argument is not persuasive, at least with respect to the embodiment of Seiji illustrated in Figs. 1-3. As shown in the annotated Fig. 1 of Seiji provided in the rejection of claim 1 above, Seiji does disclose first and second horizontal planes having the configuration required by claims 1 and 23. As such, Applicant’s arguments are not persuasive.
Conclusion
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/EVAN H MACFARLANE/Examiner, Art Unit 3724
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