Safety brake for a circular saw blade, circular saw including the safety brake, and method of operating a circular saw

Abstract

This disclosure relates to a safety brake (100) suitable for a circular saw blade (40), a circular saw (10) including the safety brake (100), and a method of operating the circular saw (10). The safety brake (100) includes a sensor assembly (110), a brake assembly (120), and an actuator assembly (160). The sensor assembly (110) is configured to detect an actuation parameter and generate a trigger signal in response to detecting the actuation parameter. The brake assembly (120) includes a brake cam (130) and a brake pad (190). The brake cam (130) is configured to selectively transition between a disengaged configuration and an engaged configuration and is configured to operably engage a flat side surface of the circular saw blade (40). The brake pad (190) includes a pad friction material (192) and is positioned such that the pad friction material (192) faces the brake cam (130). The actuator assembly (160) is configured to selectively transition the brake cam (130) from the disengaged configuration to the engaged configuration in response to receiving the trigger signal.

Description

[0001] Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 046,924, filed on July 1, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to safety brakes for circular saw blades, circular saws including the safety brakes, and / or methods of operating a circular saw. Background Art

[0004] Circular saws utilize a rotating circular saw blade to cut workpieces. The rotating circular saw blade is typically sharp and can pose a safety hazard to the user of the circular saw in some cases. Many circular saws include blade guards and / or other mechanisms to protect the user from contact with the rotating circular saw blade. However, it may still be desirable to have auxiliary and / or additional safety mechanisms in place. Some such auxiliary and / or additional safety mechanisms have been developed; however, they are typically single-use safety mechanisms that can be destructive to at least one component of the circular saw blade and / or the safety mechanism. Additionally or alternatively, known auxiliary and / or additional safety mechanisms may not be suitable for installation in a wide range of circular saws including larger stationary circular saws and smaller and / or portable circular saws. Accordingly, there is a need for an improved safety brake adapted for a circular saw blade, a circular saw including the safety brake, and / or a method of operating a circular saw. Summary of the Invention

[0005] Disclosed herein are a safety brake adapted for a circular saw blade, a circular saw including the safety brake, and a method of operating a circular saw. The safety brake includes a sensor assembly, a brake assembly, and an actuator assembly. The sensor assembly is configured to detect an actuation parameter and generate a trigger signal in response to detecting the actuation parameter. The brake assembly includes a brake cam and a brake pad. The brake cam is configured to selectively transition between a disengaged configuration and an engaged configuration, wherein in the disengaged configuration, the brake cam is spaced apart from a blade receiving region of the safety brake, and in the engaged configuration, the brake cam extends into the blade receiving region and is configured to operably engage a flat side surface of the circular saw blade and resist rotation of the circular saw blade. The brake pad includes a pad friction material and is positioned relative to the brake cam such that the pad friction material faces the brake cam. The actuator assembly is configured to selectively transition the brake cam from the disengaged configuration to the engaged configuration in response to receiving the trigger signal from the sensor assembly.

[0006] The method includes rotating a circular saw blade of a circular saw and using a sensor assembly to detect that a distance between an individual and the circular saw blade is less than a threshold distance. The method further includes stopping rotation of the circular saw blade in response to the detection. The stopping includes using a brake assembly of the circular saw. The brake assembly includes a brake cam and a brake pad, and the stopping includes operably engaging a flat side surface of the circular saw blade with the brake cam and pressing the circular saw blade between the brake cam and the brake pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram of an example of a safety brake suitable for a circular saw according to the present disclosure, illustrating the safety brake in a disengaged configuration.

[0008] Figure 2 is Figure 1 an illustration of an example of a safety brake, where the safety brake is illustrated in an engaged configuration.

[0009] Figure 3 is a simplified contour diagram of an example of a safety brake and a circular saw blade according to the present disclosure.

[0010] Figure 4 is a simplified contour diagram of a hand-held circular saw including a safety brake according to the present disclosure.

[0011] Figure 5 is a simplified contour diagram of a miter saw including a safety brake according to the present disclosure.

[0012] Figure 6 is a simplified cross-sectional view of a region of a circular saw including a safety brake according to the present disclosure, illustrating the safety brake in a disengaged configuration.

[0013] Figure 7 is Figure 6 an illustration of a circular saw, illustrating the safety brake in an intermediate configuration.

[0014] Figure 8 is Figures 6 - 7 an illustration of a circular saw, illustrating the safety brake in an engaged configuration.

[0015] Figure 9 is another simplified cross-sectional view of a region of a circular saw including a safety brake according to the present disclosure.

[0016] Figure 10 is a simplified illustration of a cam according to the present disclosure, the cam including a region of increasing radius and a region of constant radius and which can be used with a safety brake and / or a circular saw.

[0017] Figure 11 is a schematic illustration of a cam in accordance with the present disclosure, the cam including an eccentric profile and being usable with a safety brake and / or a circular saw.

[0018] Figure 12 is a side view in schematic form of a safety brake and a circular saw blade in accordance with the present disclosure, showing an adjustment mechanism and a reset mechanism in accordance with the present disclosure.

[0019] Figure 13 is a schematic illustration of a reset mechanism in accordance with the present disclosure.

[0020] Figure 14 is Figure 13 another view of the reset mechanism of

[0021] Figure 15 is Figures 13 - 14 another view of the reset mechanism of

[0022] Figure 16 is a schematic diagram of an example of another reset mechanism in accordance with the present disclosure.

[0023] Figure 17 is a schematic diagram of a brake assembly including a pivot pad mount in accordance with the present disclosure.

[0024] Figure 18 is a schematic diagram of an example of another reset mechanism in accordance with the present disclosure.

[0025] Figure 19 is a schematic diagram of an example of another reset mechanism in accordance with the present disclosure.

[0026] Figure 20 is a schematic diagram of an example of another reset mechanism in accordance with the present disclosure.

[0027] Figure 21 is a flow chart showing an example of a method of operating a circular saw in accordance with the present disclosure. DETAILED DESCRIPTION

[0028] Figures 1 - 21 Examples of a safety brake 100 for a circular saw blade 40 suitable for a circular saw 10, examples of a circular saw 10 including the safety brake 100, and / or examples of various steps in a method 1000 of operating a circular saw are provided. Elements for like or at least substantially like purposes are labeled with like reference numerals in Figures 1 - 21 each of the figures, and these elements may not be discussed in detail herein with reference to Figures 1 - 21 each of the figures. Similarly, not all elements may be labeled in Figures 1 - 21 each of the figures, but for consistency, the reference numerals associated therewith may be used herein. Referring to Figures 1 - 21The elements, components, and / or features discussed in one or more of the figures may be included in Figures 1 - 21 any one of the figures and / or used in conjunction with Figures 1 - 21 any one of Figure One without departing from the scope of the present disclosure.

[0029] Generally, elements that may be included in a particular embodiment are shown in solid lines, while optional elements are shown in dashed lines. However, elements shown in solid lines may not be necessary for all embodiments and may be omitted in some embodiments without departing from the scope of the present disclosure.

[0030] A circular saw 10 according to the present disclosure that may include and / or utilize a safety brake 100 and / or its components is schematically shown in Figures 1 - 2 and is shown in simplified form in Figures 3 - 20 As best shown in Figures 1 - 2 , the circular saw 10 includes a motor 20, a mandrel 30, and a circular saw blade 40. The motor includes a motor shaft 22 configured to rotate about an axis of rotation 24. The mandrel is operatively attached directly or indirectly to the motor shaft. The circular saw blade is operatively attached to the circular saw via the mandrel. The circular saw 10 further includes a safety brake 100 that defines a blade receiving area 102, and the circular saw blade 40 extends at least partially within the blade receiving area.

[0031] During operation of the circular saw 10, and as discussed in more detail herein, the motor 20 can be used to provide motive power to rotate the motor shaft 22 and the attached circular saw blade 40 about the axis of rotation 24. As best shown in Figure 3 , 12 and 19, the circular saw blade 40 can include teeth 48, and rotation of the circular saw blade about the axis of rotation can permit and / or facilitate cutting of a workpiece with, via, and / or using the circular saw.

[0032] Compared to conventional circular saws that do not include a safety brake 100, the circular saw 10 according to the present disclosure can include additional safety features that can protect a person from injury that results from contact between the person and the circular saw blade, such as during rotation of the circular saw blade. More specifically, and as discussed in more detail herein, the circular saw 10 is configured to detect a situation where there is a likelihood of injury and immediately stop rotation of the circular saw blade in response to such detection, thereby limiting and / or avoiding injury. By transitioning the brake assembly 120 of the safety brake 100 from a disengaged configuration 140 as shown in Figure 1 and Figure 6 to an engaged configuration as shown in Figure 2 and Figure 8The engagement configuration 142 shown in FIG. may stop the rotation of the circular saw blade. This conversion from the disengaged engagement configuration to the engaged engagement configuration is also discussed in more detail herein.

[0033] In addition to the additional safety features that may be provided by the presence of the safety brake 100, the circular saw 10 may include any suitable one and / or more features common to conventional circular saws, and may include any suitable style and / or type of circular saw. For example, the circular saw 10 may include one or more of a hand-held circular saw, a miter saw, a radial arm saw, a table saw, a cutoff saw, a plunge saw, an up-cut saw, a panel saw, and / or a track saw. Figure 4 FIG. shows an example of a circular saw 10 in the form of a hand-held circular saw including a safety brake 100. Figure 5 FIG. shows an example of a circular saw 10 in the form of a miter saw including a safety brake 100. The circular saw 10 may use any suitable power source, including wired power from a power outlet and / or one or more batteries, and may be referred to herein as a wired circular saw 10 and / or a wireless circular saw 10.

[0034] The motor 20 may include any suitable structure that can provide motive power for the rotation of the motor shaft 22, the arbor 30, and / or the circular saw blade 40. Examples of the motor 20 include an electric motor, an AC electric motor, a DC electric motor, a brushless DC electric motor, a variable speed motor, and / or a single speed motor. The circular saw 10 may include any suitable power source and corresponding power structure for powering the motor 20 and / or the safety brake 100, examples of which include a power cord 80 and / or a battery 85, and within the scope of the present disclosure, the same or different power sources may be used for the motor 20 and the safety brake 100.

[0035] The arbor 30 may include any suitable structure that may be operatively attached to the motor shaft 22 and / or may operatively attach the circular saw blade 40 to the circular saw 10 or may be used to operatively attach the circular saw blade 40 to the circular saw 10 such that rotation of the arbor 30 drives the rotation of the operatively coupled circular saw blade 40. Generally, the arbor 30 is configured to allow and / or facilitate selective and repeated separation of the circular saw blade from the remainder of the circular saw to allow and / or facilitate sharpening and / or replacement of the circular saw blade. Examples of the arbor 30 include a threaded arbor 30.

[0036] As Figures 1 - 2 shown by the dashed line in FIG., the circular saw 10 may include a gripping area 50. The gripping area 50 (when present) may be configured to be gripped by the user of the circular saw. Examples of the gripping area 50 include a handle.

[0037] Also as Figures 1 - 2As shown by the dashed lines in [description], the circular saw 10 may include a switch 55. When the switch 55 is present, the switch 55 may be configured to be selectively actuated by a user of the circular saw and / or selectively apply current to the motor 20 to power the motor 20. Examples of the switch 55 include an electrical switch, a normally open electrical switch, a momentary electrical switch, and / or a latching momentary switch.

[0038] Also as Figures 1 - 2 shown by the dashed lines in [description], the circular saw 10 may include a blade guard 60. The blade guard 60 (when present) may be configured to cover, receive, and / or enclose at least a portion of the circular saw blade 40 to prevent or reduce the likelihood of contact between a user and the circular saw blade. The blade guard 60 may include a retractable region 62 that may be configured to fold, rotate, and / or otherwise retract when the circular saw is used to cut a workpiece. In some examples of the circular saw 10, at least one region 64 of the blade guard 60 may be defined by and / or may include a safety brake 100. In other words, the safety brake 100 may act as at least one region 64 of the blade guard 60 by preventing contact between a user of the circular saw and the region of the circular saw blade 40 that extends within the blade receiving region 102. Also as Figures 1 - 2 shown by the dashed lines in [description], the circular saw 10 may include a workpiece support 70 that may be configured to support a workpiece and / or position the circular saw relative to the workpiece when the workpiece is being cut by the circular saw.

[0039] The circular saw 10 may include a clutch 90, which is also referred to herein as a safety clutch 90. When present, the clutch 90 may be configured to reduce the likelihood of damage to at least one component of the circular saw (such as the motor 20, the motor shaft 22, the arbor 30, the gear train of the circular saw, and / or the safety brake 100) when the safety brake 100 transitions from its disengaged configuration 140 to its engaged configuration 142 to stop the rotation of the circular saw blade 40. This reduction in the likelihood of damage may be achieved by at least partially mechanically separating the circular saw blade 40 from the motor shaft 22, thereby allowing the motor shaft 22 to rotate independently of the rotation of the circular saw blade 40 and reducing the rotational mass or momentum that must be stopped by the safety brake 100, and / or allowing the motor shaft 22 to stop rotating more slowly than the circular saw blade 40. The clutch 90 may be incorporated into the arbor 30, may be defined within the arbor 30, and / or may be at least partially defined by the arbor 30, by the gear train of the circular saw, and / or by the belt drive assembly of the circular saw.

[0040] The clutch 90 can be operated in any suitable manner. By way of example, the clutch 90 can be configured to selectively permit rotation or relative rotation between the circular saw blade and the motor shaft when the torque between the circular saw blade and the motor shaft exceeds a threshold torque. As another example, the clutch 90 can be configured to resist rotation or relative rotation between the circular saw blade and the motor shaft when the torque between the circular saw blade and the motor shaft is less than the threshold torque. Examples of the clutch 90 include a torque limiting clutch and a friction clutch.

[0041] As discussed in more detail herein, the circular saw 10 and / or its safety brake 100 includes a sensor assembly 110 that can be configured to detect actuation parameters. The actuation parameters can indicate that the actuator assembly should be used to actuate and / or engage the safety brake. Examples of the actuation parameters include an undesired event parameter that indicates an undesired event or the likelihood of an undesired event to be avoided by and / or with the circular saw. Another example of the actuation parameter includes a kickback parameter that indicates the kickback or the likelihood of kickback of the circular saw. Another example of the actuation parameter includes a movement parameter that indicates an undesired movement or the likelihood of an undesired movement of the circular saw. Yet another example of the actuation parameter includes a proximity parameter that indicates that the distance between an individual (such as a user of the circular saw) and the circular saw is less than a threshold distance. In various examples, and as discussed in more detail herein, the proximity parameter can indicate contact between the individual and the circular saw blade, impending contact between the individual and the circular saw blade, and / or that the distance between the individual and the circular saw blade is less than a small finite distance, examples of which are disclosed herein.

[0042] To increase the sensitivity, signal-to-noise ratio, and / or likelihood of false readings of the sensor assembly, the circular saw 10 can include a blade isolation structure 95. The blade isolation structure 95 (when present) can be configured to electrically isolate the circular saw blade 40 from at least one other component of the circular saw. Examples of at least one other component of the circular saw include the grip area 50, the switch 55, the outer surface of the circular saw, and / or areas of the circular saw that would be touched by a user when the circular saw is used to cut a workpiece. Additionally or alternatively, the blade isolation structure 95 can be configured to electrically isolate the circular saw blade 40 from ground or earth ground.

[0043] Thus, the safety brake 100 has so far been described as being included in and / or as a component of the circular saw 10. Within the scope of the present disclosure, the safety brake 100 can be incorporated into the circular saw 10 in any suitable manner. As an example, the circular saw 10 can be provided by its manufacturer with the safety brake 100 already incorporated in and / or included therein. As another example, the safety brake 100 can be configured to be included in, attached to, and / or retrofitted into an existing circular saw that does not necessarily include the safety brake 100 when initially manufactured and / or sold by the manufacturer. With this in mind, the following discussion of the safety brake 100 can refer to the safety brake 100 incorporated into the circular saw 10 and / or the safety brake 100 that can be manufactured and / or sold as a replacement safety brake 100 suitable for the circular saw 10, and / or the safety brake 100 that can be manufactured and / or sold for retrofitting and installing on an existing circular saw that does not include a safety brake.

[0044] As Figures 1 - 9 and Figures 12 - 17 generally shown, and with reference Figures 1 - 2 , the safety brake 100 is configured to function as a safety brake for the circular saw blade 40 suitable for the circular saw 10. The safety brake 100 includes a sensor assembly 110, a brake assembly 120, and an actuator assembly 160. As discussed, the sensor assembly 110 is configured to detect actuation parameters, examples of which are disclosed herein. The actuation parameters indicate that the actuator assembly should be used to actuate and / or engage the safety brake to stop the rotation of the circular saw blade. In other words, the sensor assembly 110 can be configured to detect an unsafe condition, such as the likelihood of contact and / or actual contact between an individual and the circular saw blade. The sensor assembly 110 can be configured to generate a trigger signal 112 in response to the detection of an actuation parameter, which is shown in Figures 1 - 2 .

[0045] In some examples, the sensor assembly 110 can be configured to generate a trigger signal in response to or immediately in response to contact or the onset of contact between an individual and the circular saw blade. In some such examples, the sensor assembly can be referred to herein as generating a trigger signal in response to the distance between an individual and the circular saw blade being negligible and / or zero. In some examples, the sensor assembly 110 can be configured to generate a trigger signal in response to the distance between an individual and the circular saw blade being a small finite distance. Examples of such a small finite distance include distances less than 5 millimeters (mm), less than 4 mm, less than 3 mm, less than 2 mm, less than 1 mm, or less than 0.5 mm. In some such examples, the small finite distance is greater than zero.

[0046] The brake assembly 120 includes a brake cam 130. The brake assembly 120 and / or its brake cam 130 can be configured to transition between a disengaged configuration 140 as shown in Figure 1 and an engaged configuration 142 as shown in Figure 2 . When in the disengaged configuration 140, the brake cam is spaced from and / or does not contact the saw blade receiving area 102 of the safety brake 100 and the saw blade 40 of the circular saw 10, as shown in Figure 1 . In contrast, when in the engaged configuration 142, the brake cam extends into the saw blade receiving area 102 and is configured to operably engage the flat side surface 42 of the circular saw blade 40 to resist and / or stop the rotation of the circular saw blade.

[0047] The actuator assembly 160 is configured to selectively transition the brake assembly 120 and / or its brake cam 130 from the disengaged configuration to the engaged configuration. This selective transition can be performed in response to and / or as a result of receiving a trigger signal from the sensor assembly and / or by the actuator assembly. This selective transition is schematically shown in Figures 1 - 2 by the transition from the configuration of Figure 1 to the configuration of Figure 2 . This selective transition is also shown schematically in Figures 6 - 8 , where Figure 6 illustrates the cam 130 spaced from the circular saw blade 40 and in the disengaged configuration 140, Figure 7 illustrates the actuator assembly 160, which pushes the cam 130 into initial contact with the circular saw blade 40 such that the cam is in an intermediate configuration 141, and Figure 8 illustrates the cam 130 in contact with the circular saw blade 40, in the engaged configuration 142 and resisting the rotation of the circular saw blade.

[0048] The brake assembly 120 can include any suitable structure that includes a brake cam 130 and can be adapted, configured, designed, and / or constructed to selectively stop the rotation of the circular saw blade and / or selectively transition between a disengaged configuration 140 and an engaged configuration 142. In some examples, the brake assembly 120 can include and / or be a non-destructive brake assembly 120 that can be configured to selectively stop the rotation of the circular saw blade without damaging the circular saw blade and / or the brake assembly. In some examples, the brake assembly 120 additionally or alternatively can include and / or be a resetable brake assembly that can be configured to selectively and repeatedly transition between a disengaged configuration and an engaged configuration, as discussed in more detail herein. In some examples, the brake assembly 120 can include only one or a single brake cam 130; however, within the scope of the present disclosure, the brake assembly 120 can include more than one brake cam 130, such as a plurality of brake cams 130.

[0049] As discussed, the brake assembly 120 and / or its brake cam 130 can be configured to selectively engage the flat side surface 42 of the circular saw blade 40. In view of this, the brake cam 130 can be referred to herein as not engaging the teeth 48 of the circular saw blade and / or as being spaced apart from the teeth of the circular saw blade. This can include not engaging the teeth and / or being spaced apart from the teeth when the brake cam is in the disengaged configuration 140 and when the brake cam is in the engaged configuration 142.

[0050] As from Figure 1 the configuration to Figure 2 the configuration and from Figure 6 the configuration to Figure 8 the configuration transitions shown, the brake cam 130 can be configured to rotate about a cam rotation axis 138 to selectively transition from the disengaged configuration 140 to the engaged configuration 142 and / or transition between the disengaged configuration and the engaged configuration, or when the brake cam selectively transitions, from the disengaged configuration 140 to the engaged configuration 142 and / or transition between the disengaged configuration and the engaged configuration. In some examples, the blade receiving area 102 can include and / or be a flat or at least substantially flat blade receiving area 102. In some such examples, the cam rotation axis 138 can be parallel to or at least substantially parallel to the flat blade receiving area. In other words, the cam rotation axis 138 can be parallel to or at least substantially parallel to the flat side surface 42 of the circular saw blade 40. In some examples, the cam rotation axis 138 can be perpendicular to or at least substantially perpendicular to the actuation axis 166 of the actuator assembly 160.

[0051] As Figures 1 - 2 the dashed lines in Figure 9As shown by the solid lines in, the brake cam 130 may include a cam biasing mechanism 144. The cam biasing mechanism 144 may be configured to bias the brake cam 130 toward and / or into the disengaged configuration 140. In other words, the cam biasing mechanism 144 may keep the brake cam 130 in the disengaged configuration 140 unless the brake cam is pushed from the disengaged configuration and / or toward the engaged configuration 142, such as by an actuator assembly 160. Examples of the cam biasing mechanism 144 include an elastic cam biasing mechanism, a cam biasing spring, and / or a cam biasing torsion spring.

[0052] The brake cam 130 may have and / or define a saw blade engagement surface 134, which may be configured to operably engage a flat side surface 42 of the circular saw blade 40, such as when the brake cam is in the engaged configuration 142. In some examples, the saw blade engagement surface 134 may be shaped such that as the brake cam rotates about the cam rotation axis 138 and / or as the brake cam transitions from the disengaged configuration 140 to the engaged configuration 142, the brake cam presses more and more strongly against the flat side surface of the circular saw blade.

[0053] In some such examples, the brake cam 130 may include a region 158 of increasing radius and a region 159 of constant radius, examples of which are schematically illustrated in Figures 1 - 2 shown in, Figures 6 - 8 illustrated in dashed lines in, and Figure 10 more clearly illustrated in. As best shown in Figure 10 the distance between the cam rotation axis 138 and the saw blade engagement surface 134 increases within the region 158 of increasing radius until the distance matches the radius of the region 159 of constant radius, as indicated by the dashed circle.

[0054] In some such examples, the brake cam may be configured to initially engage the circular saw blade with the region of increasing radius and then engage the circular saw blade with the region of constant radius. Within the region of increasing radius, and as discussed, the distance between the cam rotation axis 138 and the saw blade engagement surface 134 may increase in a plane perpendicular to the cam rotation axis, so that as the brake cam rotates in contact with the circular saw blade, the brake cam presses against the circular saw blade with an increasingly stronger force. Within the region of constant radius, and also as discussed, the distance between the cam rotation axis 138 and the saw blade engagement surface 134 may be constant in a plane perpendicular to the cam rotation axis, such that as the brake cam further rotates in contact with the saw blade, the brake cam presses against the circular saw blade with a constant or at least substantially constant force.

[0055] In some examples, the saw blade engagement surface 134 may be shaped such that the brake cam automatically stops the circular saw blade 40 and / or automatically transitions to the engaged configuration in response to contact between the brake cam and the flat side surface of the circular saw blade.

[0056] In some examples, the saw blade engagement surface 134 may have and / or define an eccentric profile or shape relative to the cam rotation axis 138. As an example, and as Figure 11 shown, the saw blade engagement surface 134 may have and / or define a constant radius of curvature, such as may be indicated by the dashed circle in Figure 11 . However, the center point 135 of this radius of curvature may be offset from the cam rotation axis 138 such that when the cam rotates further into contact with the circular saw blade (such as in the Figure 11 clockwise direction in), the saw blade engagement surface presses against the circular saw blade with a greater force.

[0057] As another example, the saw blade engagement surface 134 may have and / or define a logarithmic spiral profile or shape. The specific shape and / or profile of the saw blade engagement surface 134 may be designed and / or selected based on the coefficient of friction between the flat side surface 42 and the brake cam 130 so as to provide the desired stopping force to the saw blade 40 when the brake cam transitions to the engaged configuration. As another example, the friction between the brake cam and the flat side surface, once initiated, may push and / or urge the brake cam toward the engaged configuration.

[0058] In other words, the safety brake 100, the brake cam 130, and / or the saw blade engagement surface 134 may be configured such that during rotation of the circular saw blade, the frictional force between the circular saw blade and the brake cam pushes the brake cam toward the engaged configuration 142 and / or into the engaged configuration 142. Thus, and once the actuator assembly 160 pushes the brake cam 130 into contact with the circular saw blade 40, the frictional force may cause the brake cam to apply an increasing stopping force on the circular saw blade until rotation of the circular saw blade stops. This configuration may be referred to herein as a self - augmenting safety brake.

[0059] In some examples, the brake cam 130 may include a cam friction material 136, which may define the saw blade engagement surface 134 and / or which may be selected to increase the coefficient of friction between the saw blade engagement surface and the circular saw blade. Examples of the cam friction material 136 include diamond coatings, abrasive materials, abrasive grit coatings, ceramic materials, sintered materials, and / or metal alloys.

[0060] In some examples, the saw blade engagement surface 134 can be integral with and / or defined by the brake cam 130. In other examples, the saw blade engagement surface can be applied to and / or can coat the brake cam. In other examples, the brake cam 130 can include a saw blade engagement surface insert 132, as Figures 1 - 2 shown. The saw blade engagement surface insert 132 (when present) can be operatively attached to the remainder of the brake cam, can form and / or define the saw blade engagement surface 134, and / or can include and / or be defined by the cam friction material 136. In some such examples, the brake cam 130 and / or the saw blade engagement surface insert 132 can be configured to be repaired and / or replaced, such as after a threshold amount of wear and / or after the brake cam is transitioned from a disengaged configuration to an engaged configuration a threshold number of times. Additionally or alternatively, the brake cam 130 can be configured to be repaired and / or replaced.

[0061] The safety brake 100, the brake assembly 120, and / or the brake cam 130 can be configured such that when transitioning from the disengaged configuration 140 to the engaged configuration 142, the brake cam remains in the engaged configuration. Such a safety brake 100, brake assembly 120, and / or brake cam 130 can be referred to herein as and / or can be a self-locking safety brake 100, a self-locking brake assembly 120, and / or a self-locking brake cam 130, respectively. As an example, the safety brake 100, the brake assembly 120, and / or the brake cam 130 can be configured to remain in the engaged configuration until the brake cam is released from the engaged configuration, such as by a user of the circular saw. In other words, and as discussed in more detail herein, it may be necessary for the user of the circular saw to actuate the reset mechanism 146 to transition the brake assembly 120 from the engaged configuration to the disengaged configuration. This can further increase the safety of the circular saw 10 including the safety brake 100, such as by forcing the user to confirm and / or correct the condition(s) that caused the brake assembly to transition to the engaged configuration prior to subsequent operation of the circular saw.

[0062] The safety brake 100, the brake assembly 120, and / or the brake cam 130 can utilize any suitable mechanism to remain in and / or within the engaged configuration. As an example, the brake cam 130 can be shaped to remain in the engaged configuration. As a more specific example, the brake cam 130 can include a locking region and / or a flat region that holds the brake cam in the engaged configuration. As another example, the operative engagement and / or force between the circular saw blade and the brake cam can hold the brake cam in the engaged configuration.

[0063] The brake assembly 120 can include a stop 170, as Figures 1 - 2As shown. The stop 170 (when present) can be configured to limit the rotation of the braking cam 130, such as rotation about the cam rotation axis 138. In some examples, the stop 170 can include a disengaged configuration stop 172, which can be configured to limit the rotation of the braking cam away from the saw blade receiving area 102 when the braking cam is in the disengaged configuration. In some examples, the stop 170 can include an engaged configuration stop 174, which can be configured to limit the rotation of the braking cam toward and / or into the saw blade receiving area 102 when the braking cam is in the engaged configuration, as Figure 8 shown.

[0064] Within the scope of the present disclosure, the stop 170 can be defined in any suitable manner. As an example, the stop 170 can be at least partially defined by the braking cam 130, such as by the shape and / or profile of the braking cam that limits its rotation as shown, for example, by a flat area of the cam 130, which is presented as a solid line and defines Figures 6 - 8 the engaged configuration stop 174 in. As another example, the stop 170 can be configured to operably engage the braking cam to limit the rotation of the braking cam, such as when the actuator arm 164 of the actuator assembly 160 engages the braking cam, as Figure 6 best shown in.

[0065] As Figures 1 to 3 , Figure 10 and Figures 16 to 17 shown, the brake assembly 120 can include a housing 180, which may also be referred to herein as a caliper 180. The housing 180 can be configured to operably support the braking cam 130 and / or the actuator assembly 160. Additionally or alternatively, the housing 180 can at least partially surround the saw blade receiving area 102. The housing 180 can be formed of a mechanically rigid material such as metal or plastic. This configuration can reduce deflection when the braking cam 130 transitions to the engaged configuration, and / or can reduce the time required for the braking cam to stop the rotation of the circular saw blade when transitioning from the disengaged configuration to the engaged configuration.

[0066] As Figures 1 - 3 and Figure 18 shown, the housing 180 can include a split housing that is configured to be detachable into two or more separate and / or distinct housing regions 182. In such a configuration, as discussed in more detail herein, the separation of the housing regions 182 can allow the brake assembly 120 to be reset and / or transition from the engaged configuration to the disengaged configuration.

[0067] As Figures 1 - 2 the dashed lines in and Figures 6 - 9As shown by the solid lines in, in addition to the brake cam 130, the safety brake 100 and / or its brake assembly 120 may further include a brake pad 190. The brake pad 190 (when present) may include a pad friction material 192, examples of which are disclosed herein with reference to the cam friction material 136. The brake pad 190 may be positioned within the brake assembly 120 and / or relative to the brake cam 130 such that the pad friction material 192 faces the brake cam 130, faces the saw blade receiving area 102, and / or faces the circular saw blade 40. Additionally or alternatively, the brake pad 190 may be positioned such that the saw blade receiving area 102 extends at least partially between the brake pad and the brake cam. When the brake assembly is in the engaged configuration, the brake assembly 120 may be configured such that at least one area of the circular saw blade 40 is clamped between the brake pad 190 and the brake cam 130.

[0068] In some examples, the brake pad 190 may include a pivot pad mount 230, as Figures 1 - 2 and Figure 17 shown. The pivot pad mount 230 (when present) may be configured to allow limited rotation of the brake pad 190, such as about a pivot point 232. Additionally or alternatively, the pivot pad mount 230 may be configured to allow limited rotation of the brake pad 190 about at least one pivot axis or even about multiple pivot axes. This configuration may allow the friction surface 244 of the brake pad 190 to align with or rest flat against the circular saw blade, despite misalignment between the brake assembly 120 and / or the circular saw blade and / or despite deflection of the brake assembly and / or the circular saw blade. This may allow and / or facilitate uniform load and / or force distribution between the circular saw blade 200 and the brake pad 190 and / or its friction surface 244. This uniform load and / or force distribution between the brake pad and the saw blade may also allow and / or facilitate uniform load and / or force distribution between the brake cam and the circular saw blade. This uniform load and / or force distribution may reduce the magnitude of point forces on various components of the circular saw, which may allow the use of lighter components, may reduce component wear, and / or may increase the service life of the components. The friction surface 244 may include and / or be a flat or at least substantially flat friction surface 244, which may be configured to make at least partial or even full face-to-face contact with the flat side surface of the circular saw blade.

[0069] As Figures 1 - 2 shown by the dashed lines in and Figure 12 the solid lines in, the brake assembly 120 may include an adjustment mechanism 194. The adjustment mechanism 194 (when present) may be configured to selectively adjust or for selectively adjusting the distance 196 between the brake pad and the brake cam, as Figure 1As shown. This adjustment can allow and / or facilitate the use of circular saw blades 40 of different thicknesses within the circular saw 10, and / or can allow the safety brake 100 to define a desired spacing between the brake pad 190 and the circular saw blade, regardless of the thickness and / or other properties of the circular saw blade. For example, and as Figure 12 shown, the adjustment mechanism 194 can include detents for a predetermined and / or specific circular saw blade thickness (such as 1.5 mm and 3.2 mm in the example shown). Examples of the adjustment mechanism 194 include threaded fasteners configured to adjust the distance between the brake pad and the brake cam.

[0070] The circular saw blade 40 can include a plurality of flat side surfaces 42, including a first flat side surface 44 and a second flat side surface 46 that can be opposite the first flat side surface. In this configuration, the brake cam 130 can be configured to operably engage the first flat side surface 44, and the brake pad 190 and / or its pad friction material 192 can be configured to operably engage the second flat side surface of the circular saw blade.

[0071] As Figures 1 - 3 best shown perhaps, the safety brake 100 can include an attachment mechanism 200 that can be configured to operably attach at least a portion of the safety brake (such as the brake cam 130, the actuator assembly 160, the housing 180, and / or the brake pad 190) to the circular saw 10. In some examples, the attachment mechanism 200 can maintain a fixed or at least substantially fixed relative orientation between the saw blade receiving region 102 and the remainder of the circular saw.

[0072] In some examples, the attachment mechanism 200 can include and / or be a floating attachment mechanism configured to allow the saw blade receiving region 102 to operably translate relative to the remainder of the circular saw, such as along a floating axis 204 that can be perpendicular or at least substantially perpendicular to the flat side surface 42 of the circular saw blade. This configuration can allow the brake pad 190 to remain fixed or at least substantially fixed relative to the housing 180 during actuation of the brake assembly 120 from a disengaged configuration to an engaged configuration, while allowing both the brake pad 190 and the brake cam 130 to engage the circular saw when in the engaged configuration. One example of the floating attachment mechanism 200 includes an attachment pin 202, or a plurality of connection pins 202. In this configuration, the attachment mechanism can be configured to allow the saw blade receiving region 102 to operably translate relative to the remainder of the circular saw along the longitudinal axis of the attachment pin, such as the floating axis 204.

[0073] In some such examples, and as Figures 1 - 2As shown, the floating attachment mechanism can include a floating attachment mechanism lock 206. The floating attachment mechanism lock 206 (when present) can be selectively configured to allow and selectively configured to restrict the operative translation of the saw blade receiving area 102 relative to the remainder of the circular saw. As an example, the floating attachment mechanism lock 206 can be configured to allow the operative translation of the saw blade receiving area 102 relative to the remainder of the circular saw to facilitate the operative alignment between the saw blade receiving area and the circular saw blade. Subsequently, the floating attachment mechanism lock 206 can be configured to restrict the operative translation, such as during the operation of using the circular saw to cut a workpiece.

[0074] The actuator assembly 160 can include any suitable structure that can be adapted, configured, designed, and / or constructed to selectively convert the brake cam from the disengaged configuration to the engaged configuration in response to receiving a trigger signal from the sensor assembly. Examples of the actuator assembly 160 include an electric actuator assembly, a pneumatic actuator assembly, a hydraulic actuator assembly, and / or an explosive actuator assembly. Additional examples of the actuator assembly 160 include a solenoid, a pneumatic cylinder, a hydraulic cylinder, an explosive charge, a shape memory alloy actuator assembly, a magnetoresistive actuator assembly, a piezoelectric actuator assembly, a thermal actuator assembly, a permanent magnet actuator assembly, and / or an electroactive polymer actuator assembly. Other examples of the actuator assembly 160 include an actuator assembly biasing mechanism 168, such as an elastic biasing mechanism, a spring, a mechanical spring, a preloaded spring, and / or a pre-tensioned spring.

[0075] In a specific example, the actuator assembly 160 can include both an actuator biasing mechanism and a release mechanism 169, and the release mechanism 169 can be configured to release the actuator assembly biasing mechanism, thereby allowing the elastic biasing mechanism to push the brake cam from the disengaged configuration to the engaged configuration in response to receiving the trigger signal. In other words, the release mechanism can be configured to selectively allow the actuator assembly biasing mechanism to convert the brake cam from the disengaged configuration to the engaged configuration, and this selective actuation can be in response to the release mechanism's receipt of the trigger signal.

[0076] The actuator assembly 160 can include a power source 162, as Figure 1 and 2 shown. The power source 162 can be configured to power the actuator assembly. In some examples, the power source 162 can be configured to supply power to the actuator assembly even when the main power source of the circular saw is not available for the motor 20. When the actuator assembly 160 includes an electric actuator assembly, the power source 162 can include and / or be a power source, such as a battery and / or a capacitor.

[0077] The actuator assembly 160 can include an actuator arm 164, as Figure 2 and Figures 6 - 8As shown. The actuator arm 164 can be configured to selectively extend from the actuator assembly and / or selectively convert the brake cam from a disengaged configuration to an engaged configuration. The actuator assembly 160 additionally or alternatively can include an electromagnet that can be configured to selectively convert the brake cam from a disengaged configuration to an engaged configuration. In a specific example, the actuator assembly 160 includes an actuator solenoid that includes the actuator arm 164 in the form of a solenoid armature. In this example, the solenoid armature can be configured to operably engage the brake cam to convert the brake cam from a disengaged configuration to an engaged configuration. As Figure 2 and Figures 6 - 8 shown, when the cam is converted from a disengaged configuration to an engaged configuration, the actuator arm 164 in the form of a solenoid armature can be in direct physical contact with the cam 130. In other words, the brake assembly 120 can be without an intermediate mechanical and / or pivot linkage interconnecting the actuator arm and the brake cam. Such a configuration can reduce the total mass of the moving parts within the brake assembly and / or can increase the speed at which the brake assembly is converted from a disengaged configuration to an engaged configuration.

[0078] The sensor assembly 110 can include any suitable structure that can be adapted, configured, designed, and / or constructed to detect an actuation parameter and / or generate a trigger signal. Examples of the sensor assembly 110 include a capacitive sensor assembly configured to detect an actuation parameter. Additional examples of the sensor assembly 110 according to the present disclosure and / or other components that can be incorporated into the circular saw 10 and / or the safety brake 100 and / or used with the circular saw 10 and / or the safety brake 100 are disclosed in U.S. Patents Nos. 7,536,238, 7,971,613, and 9,724,840 and International Patent Application Publication No. WO 2017 / 0210091, the entire disclosures of which are incorporated herein by reference.

[0079] As Figures 1 - 2 the dashed line in Figure 9 and the solid line in shown, the safety brake 100 can include a deflection mitigation structure 210 that can at least partially define a saw blade receiving area 102. The deflection mitigation structure 210 (when present) can be configured to resist deflection of the saw blade 40 into contact with the brake cam 130 when the circular saw is used to cut a workpiece and the brake cam is in a disengaged configuration. In other words, and in some examples, the workpiece can cause the circular saw blade to deflect toward the brake cam. As discussed herein, the brake cam 130 can be configured such that upon contact with the rotating circular saw blade, the brake cam automatically converts to an engaged configuration, such as via frictional force between the circular saw blade and the brake cam. During normal cutting operations of the circular saw or in the absence of detection of an actuation parameter, such a conversion can be undesirable. Accordingly, the deflection mitigation structure 210 can be used to reduce the likelihood of such an undesirable contact between the circular saw blade and the brake cam.

[0080] The deflection mitigation structure 210 can resist contact between the circular saw blade and the brake cam in any suitable manner. As an example, the deflection mitigation structure 210 can include a deflection mitigation surface 212, as Figures 1 - 2 shown, which can be configured to operably contact the circular saw blade 40 when the circular saw blade deflects toward the brake cam. More specifically, the deflection mitigation surface 212 can be positioned to contact the circular saw blade 40 before the circular saw blade deflects into contact with the brake cam. As a result, the deflection mitigation surface 212 can prevent the circular saw blade from deflecting into contact with the brake cam.

[0081] As discussed in more detail herein with reference to the blade isolation structure 95, it may be desirable to electrically insulate the circular saw blade 40 from one or more other components of the circular saw 10. In view of this, at least the deflection mitigation surface 212 of the deflection mitigation structure 210 can be electrically isolated from the remainder of the circular saw.

[0082] In some examples, the deflection mitigation structure 210 can include an electrical isolation structure 214, which can also be referred to herein as an electrical insulation spacer 214, that electrically isolates the circular saw blade from one or more other components of the circular saw during contact between the deflection mitigation structure and the circular saw blade. Examples of electrical isolation structures include electrical insulators.

[0083] In some examples, the deflection mitigation structure 210 can be defined by an electrically insulating material that defines the deflection mitigation surface 212. As a specific example, the deflection mitigation structure 210 can be at least partially or even completely defined by a ceramic material.

[0084] As discussed, after transitioning to the engaged configuration 142, the safety brake 100 can be configured to remain in the engaged configuration at least until the user of the circular saw transitions the circular saw to the disengaged configuration. In view of this, the safety brake 100 can include a reset mechanism 146, which can be configured to either allow the user of the circular saw to selectively transition the brake cam from the engaged configuration to the disengaged configuration to allow the circular saw to continue to be used to cut a workpiece.

[0085] Examples of the reset mechanism 146 include an eccentric structure 148, such as an eccentric shaft, an eccentric bushing, and / or an eccentric bearing. This is shown in Figures 6 - 9 and Figures 13 - 15 shown. As Figures 13 - 15 best shown in, the eccentric structure 148 can have an eccentric lobe and / or can be configured to rotate to move the brake cam 130 away from the circular saw blade 40, e.g., as shown by the transition from Figure 13 the engaged configuration 142 shown to Figure 14 the disengaged configuration 140 shown. After moving away from the circular saw blade, as Figure 14As shown by the dashed arrow in, the brake cam 130 can be automatically pushed to rotate to the disengaged configuration by the cam biasing mechanism. In some examples, and as Figure 1 shown in, the safety brake 100 can include a pre-tensioning rod 156 that can be configured to rotate or selectively rotate an eccentric structure.

[0086] Another example of the reset mechanism 146 includes an adjustment mechanism 194 that can be used to move the brake pad away from the circular saw blade, thereby allowing the brake cam to return to the disengaged configuration. In such an example, a tool such as a hex wrench can be used to loosen the adjustment mechanism, thereby moving the brake pad 190 away from the circular saw blade and allowing the brake cam to return to the disengaged configuration.

[0087] Yet another example of the reset mechanism 146 includes a housing 180 having different housing regions 182 that can be separated, such as via fasteners 184, as Figure 18 shown in, thereby allowing the brake cam to return to the disengaged configuration. Yet another example of the reset mechanism 146 includes a pressure-actuated reset mechanism 150, as Figure 16 shown in. The pressure-based reset mechanism 150 can be configured to release and / or reduce the pressure applied to the brake pad 190 and / or the brake cam 130 to allow the brake cam and / or the brake pad to translate away from the saw blade receiving area 102 and / or translate out of contact with the circular saw blade, thereby allowing the brake cam to return to the disengaged configuration via the action of the cam biasing mechanism 144. As an example, the pressure-actuated reset mechanism 150 can include a hydraulic cylinder that is depressurized to move the brake pad 190 and / or the brake cam 130 away from the circular saw blade and / or out of contact with the circular saw blade, thereby allowing the brake cam to return to the disengaged configuration.

[0088] Yet another example of the reset mechanism 146 can include rotating the circular saw blade 40 in a direction opposite to the direction in which the circular saw blade rotates when powered by the motor 20. This is shown in Figure 19 and can be achieved by pressing the circular saw blade against a workpiece. Additionally or alternatively, a tool such as a hex wrench can be used to rotate the mandrel 30 in a direction opposite to the direction in which the circular saw blade rotates when powered by the motor 20. In each case, this rotation can cause the brake cam 130 to rotate toward the disengaged configuration, thereby reducing the force applied by the brake cam to the circular saw blade. After rotating at least a threshold angle, the brake cam can return to the disengaged configuration, for example, via the action of the cam biasing mechanism 144.

[0089] Another example of the reset mechanism 146 includes a cam rotation structure 152, as Figures 1 - 2 andFigure 20 as shown. The cam rotation structure 152 can be attached to, selectively attached to, and / or associated with the brake cam 130, and / or can be configured to selectively rotate the brake cam away from the circular saw blade. For example, the cam rotation structure 152 can be configured to be selectively actuated by a user to rotate the brake cam away from the circular saw blade, such as by engaging the cam engagement structure 153 with the tool. In some such examples, the cam rotation structure 152 can include and / or be a cam rotation tool 154, such as a wrench. In other examples, the cam rotation tool can be permanently or at least substantially permanently attached to the safety brake and / or can be configured to selectively engage or interlock with the brake cam, such as engage or interlock with the cam engagement structure 153 of the brake cam, as Figure 20 shown. The cam rotation tool can be used to rotate the brake cam away from the circular saw blade. In some examples, the cam rotation structure can include and / or be a pre-tensioning rod 156, such as which can be tensioned by a rod spring 157, as Figure 20 shown.

[0090] As discussed, the safety brake 100 can be used to protect the user of the circular saw 10 from injury, such as injury that may be caused by contact between the user and the rotating circular saw blade 40. To facilitate such protection, the brake assembly 120 can be configured to transition the brake cam 130 from a disengaged configuration to an engaged configuration within a threshold transition time. Examples of the threshold transition time include a threshold transition time of at least 0.1 millisecond (ms), at least 0.5 ms, at least 1 ms, at least 2 ms, at least 3 ms, at least 4 ms, at least 5 ms, at most 10 ms, at most 9 ms, at most 8 ms, at most 7 ms, at most 6 ms, at most 5 ms, at most 4 ms, at most 3 ms, and / or at most 2 ms.

[0091] The speed at which the brake cam 130 transitions from the disengaged configuration to the engaged configuration can be measured and / or quantified in any suitable manner. As an example, a high-speed camera having a frame rate of, for example, 50,000 frames per second has been used to observe the circular saw blade and / or the brake cam during rotation of the circular saw blade. A light, such as a light-emitting diode, is also visible to the camera and is configured to illuminate in response to a trigger signal received by the actuator assembly. In such a configuration, the time required for the brake assembly 120 to transition from the disengaged configuration 140 to the engaged configuration 142 is quantified by counting the number of frames starting from when the light is illuminated until the cam reaches the engaged position. In various configurations, the observed time is within the above range. In the same manner, the time required for the brake assembly 120 to stop the rotation of the circular saw blade is quantified by counting the number of frames starting from when the light is illuminated until the rotation of the circular saw blade stops. In various configurations, the observed time is within the above range.

[0092] In some examples, and as Figures 1 - 2 shown by the dashed lines in, the circular saw 10 and / or the safety brake 100 may include an interlock assembly 220. The interlock assembly 220 (when present) may be configured to allow or selectively allow current to be supplied to the motor 20 when the safety brake 100 is configured to selectively resist the rotation of the circular saw blade. Additionally or alternatively, the interlock assembly 220 may be configured to prevent or selectively prevent current from being supplied to the motor when at least one component of the safety brake is not configured or cannot selectively resist the rotation of the circular saw blade. In other words, the interlock assembly 220 may be configured to allow the motor to rotate the circular saw blade when the configuration of the safety brake 100 is such that the safety brake will protect an individual from contact with the rotating circular saw blade, and the interlock assembly 220 may be configured to not allow the motor to rotate the circular saw blade when the configuration of the safety brake 100 is such that the safety brake cannot protect an individual from contact with the rotating circular saw blade.

[0093] As an example, the interlock assembly 220 may include a sensor status detector configured to indicate the status of the sensor assembly 110. In some such examples, if the sensor status detector indicates that the sensor assembly is not configured to detect an actuation parameter, such as may be caused by a failure of the sensor assembly and / or electrical interference with the sensor assembly, the interlock assembly 220 may not allow the motor to drive the rotation of the circular saw blade. Additionally or alternatively, if the sensor status detector indicates that the sensor assembly is configured to detect an actuation parameter, the interlock assembly may allow the motor to drive the rotation of the circular saw blade.

[0094] As another example, the interlock assembly 220 may include a brake assembly status detector configured to indicate the status of the brake assembly 120. In some such examples, if the brake assembly status detector indicates that the brake assembly is not configured to selectively resist the rotation of the circular saw blade, such as may be caused by a failure of the brake assembly, a misalignment of the brake assembly, and / or an operator's failure to correctly reset the brake assembly, the interlock assembly 220 may not allow the motor to drive the rotation of the circular saw blade. Additionally or alternatively, if the brake assembly status detector indicates that the brake assembly is configured to selectively resist the rotation of the circular saw blade, the interlock assembly may allow the motor to drive the rotation of the circular saw blade.

[0095] As yet another example, the interlock assembly 220 can include an actuator assembly status detector configured to indicate the status of the actuator assembly 160. In some such examples, if the actuator assembly status detector indicates that the actuator assembly is not configured to selectively urge the brake cam into contact with the circular saw blade, such as may be caused by a failure of the actuator assembly and / or debris accumulation near the actuator assembly and / or the brake cam, the interlock assembly 220 may not permit rotation of the motor-driven circular saw blade. Additionally or alternatively, if the actuator assembly status detector indicates that the actuator assembly is configured to selectively urge the brake cam into contact with the circular saw blade, the interlock assembly may permit rotation of the motor-driven circular saw blade.

[0096] The interlock assembly 220 can additionally or alternatively include any suitable structure that can be adapted, configured, designed, and / or programmed to permit or selectively permit the supply of current to the motor 20 when the safety brake 100 is configured to selectively resist rotation of the circular saw blade. As an example, the interlock assembly 220 can include transistors, relays, switches, electrical switches, and / or controllers. When the interlock assembly includes a controller, the controller can be programmed to control the operation of the interlock assembly and / or perform the functions of the interlock assembly disclosed herein.

[0097] A circular saw including a safety brake in accordance with the present disclosure (such as circular saw 10 including brake assembly 120) can be operated in a manner that protects an individual (e.g., a user of the circular saw) from injury caused by contact with the rotating circular saw blade of the circular saw. Such operation can be referred to herein as a method of operating a circular saw, and examples of such methods are disclosed herein. With this in mind, in accordance with the present disclosure, Figure 21 is a flow chart showing an example of a method 1000 of operating a circular saw (such as Figures 1 - 20 circular saw 10).

[0098] Method 1000 can include adjusting a distance at 1010, and include rotating the circular saw blade at 1020, detecting the distance at 1030, and stopping the rotation at 1040. Method 1000 can further include centering the circular saw blade at 1050, maintaining the brake cam in operable engagement at 1060, disengaging the brake cam at 1070, and / or repeating at least a subset of the method at 1080.

[0099] Adjusting the distance at 1010 may include adjusting the distance between the brake cam and the circular saw blade. In some examples, the adjustment at 1010 may be performed before rotation. In some such examples, the adjustment at 1010 may be performed using a floating attachment mechanism, examples of which are disclosed herein with reference to attachment mechanism 200. In some examples, and after the adjustment, the method may further include fixing, locking, and / or maintaining the adjustment, such as via a floating attachment locking mechanism of the circular saw.

[0100] Causing the circular saw blade to rotate at 1020 may include using, via, and / or utilizing the motor and / or arbor of the circular saw to cause the circular saw blade to rotate. Examples of motors are disclosed herein with reference to motor 20. Examples of arbors are disclosed herein with reference to arbor 30.

[0101] Detecting the distance at 1030 may include the distance between an individual and the circular saw blade being less than a threshold distance. The detection at 1030 may include detecting using, via, and / or utilizing a sensor assembly, examples of which are disclosed herein with reference to sensor assembly 110. Examples of the threshold distance are also disclosed herein.

[0102] Stopping the rotation at 1040 may include stopping the rotation of the circular saw blade and may be performed after the rotation at 1020 and / or in response to the detection at 1030. In other words, method 1000 may begin to stop at 1040 in response to the detection at 1030 indicating that the distance between an individual and the circular saw blade is less than the threshold distance. The stop at 1040 may include stopping using, via, and / or utilizing a brake assembly of the circular saw. Examples of brake assemblies are disclosed herein with reference to brake assembly 120.

[0103] As discussed in more detail herein, the brake assembly includes a brake cam. In view of this, the stop at 1040 includes operably engaging the flat side surface of the circular saw blade with the brake cam to stop the rotation of the circular saw blade. The stop at 1040 may further include directly engaging the solenoid armature of the solenoid of the brake assembly with the brake cam to force the brake cam into contact with the flat side surface of the circular saw blade. The stop at 1040 additionally or alternatively may include rotating the brake cam about a cam rotation axis that is perpendicular or at least substantially perpendicular to the actuation axis of the actuator assembly of the brake cam.

[0104] In some examples, the stop at 1040 may include pressing the circular saw blade between the brake cam and a brake pad of the brake assembly. In some examples, the stop at 1040 may include pivoting the friction surface of the brake pad relative to the flat side surface of the circular saw blade. The pivoting may occur during the pressing and / or may produce and / or generate the pressing.

[0105] In some examples, the stop at 1040 can include pushing a brake cam into contact with a flat sidewall surface of the circular saw blade using an actuator assembly biasing mechanism of a brake assembly. In some such examples, the stop at 1040 can further include releasing the brake cam using a release mechanism, and the pushing can be in response to the release.

[0106] Centering the circular saw blade at 1050 can include centering the circular saw blade between the brake cam and the brake pad. The centering at 1050 can be performed during and / or in response to the stop at 1040, such as via a floating attachment mechanism that attaches the brake assembly to the remainder of the circular saw.

[0107] Holding the brake cam in operative engagement at 1060 can include holding the brake cam in operative engagement with the circular saw blade. The holding at 1060 can be performed after, in response to, and / or as a result of the stop at 1040. In some examples, the holding at 1060 can include resisting rotation of the circular saw blade before actuating a reset mechanism of the circular saw. In other words, and after the stop at 1040, the holding at 1060 can cause the circular saw blade to stop rotating until the reset mechanism is actuated, thereby indicating to the user of the circular saw that they are ready to resume operation of the circular saw to cut a workpiece.

[0108] Disengaging the brake cam at 1070 can include disengaging the brake cam from the circular saw blade, and can be performed after the stop at 1040. The disengaging at 1070 can include disengaging to allow subsequent rotation of the circular saw blade, allow reuse of the circular saw blade, allow reuse of the brake assembly, and / or reset the circular saw. In some examples, the disengaging at 1070 can include disengaging without removing the circular saw blade from the circular saw, without removing the brake assembly from the circular saw, without damaging the circular saw blade, and / or without damaging the brake assembly.

[0109] The disengaging at 1070 can be performed in any suitable manner. As an example, the disengaging at 1070 can include rotating the cam away from the circular saw blade. In some such examples, the cam can be rotated away from the circular saw blade via rotation of the circular saw blade in a direction opposite to the direction of rotation when the circular saw blade is used to cut a workpiece. In some such examples, the cam can be rotated away from the circular saw blade by actuating a reset mechanism of the circular saw. In some such examples, a separate cam rotation tool can be used to disengage the cam from the circular saw blade.

[0110] Repeating at least a subset of the method at 1080 may include repeating any suitable one and / or more steps of method 1000 in any suitable manner. As an example, and after the disengaging at 1070, the repeating at 1080 may include repeating the rotation at 1020 to allow and / or facilitate cutting of a workpiece by a circular saw. In some such examples, the repeating at 1080 may include repeating without replacing the circular saw blade and / or without replacing the brake cam. In other words, and as discussed, the brake assembly may be configured for reuse or re-use without damaging and / or replacing the brake cam and / or the circular saw blade.

[0111] As used herein, the term “and / or” placed between a first entity and a second entity means (1) the first entity, (2) the second entity, and (3) one of the first entity and the second entity. Multiple entities listed with “and / or” shall be construed in the same manner, i.e., “one or more” of the entities so combined. Optionally, there may be other entities in addition to those specifically identified by the phrase “and / or”, whether related or unrelated to those specifically identified. Thus, as a non-limiting example, when used in conjunction with open-ended language such as “comprising”, a reference to “A and / or B” may, in one embodiment, refer only to A (optionally including entities other than B); in another embodiment, only to B (optionally including entities other than A); and in yet another embodiment, to both A and B (optionally including other entities). These entities may refer to elements, acts, structures, steps, operations, values, etc.

[0112] As used herein, the phrase "at least one" in reference to one or more entities shall be understood to mean at least one entity selected from any one or more of the entities listed, but not necessarily including at least one of every entity specifically listed within the entity listing, or excluding any combination of entities within the entity listing. This definition also allows for entities other than those specifically identified within the entity listing referred to by the phrase "at least one" to optionally exist, whether related or unrelated to those specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") can, in one embodiment, refer to at least one A, optionally including more than one A, without B (and optionally including entities other than B); in another embodiment, refer to at least one B, optionally including more than one B, without A (and optionally including entities other than A); and in yet another embodiment, refer to at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other entities). In other words, the phrases "at least one", "one or more", and "and / or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, the expressions "at least one of A, B, and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C", and "A, B, and / or C" can mean A alone, B alone, C alone, A and B together, A and C together, B and C together, A, B, and C together, and any of the foregoing optionally in combination with at least one other entity.

[0113] In the event that any patent, patent application, or other reference is incorporated herein by reference and (1) defines a term in a manner inconsistent with the unincorporated portion of the present disclosure or any other incorporated reference or (2) otherwise defines a term in a manner inconsistent with the unincorporated portion of the present disclosure or any other incorporated reference, the unincorporated portion of the present disclosure shall govern, and the term or the incorporated disclosure shall be construed only with respect to the reference that defines the term and / or the originally existing incorporated disclosure.

[0114] As used herein, the terms "adapted" and "configured" mean that an element, component, or other subject is designed and / or intended to perform a given function. Thus, the use of the terms "adapted" and "configured" should not be construed to mean that a given element, component, or other subject is merely "able to" perform a given function, but rather that the element, component, and / or other subject has been specifically selected, created, implemented, utilized, programmed, and / or designed to perform that function. Also within the scope of the present disclosure is that an element, component, and / or other recited subject that is recited as being adapted to perform a particular function may additionally or alternatively be described as being configured to perform that function, and vice versa.

[0115] As used herein, the phrases "for example", "as an example", and / or simply the term "example", when used in reference to one or more components, features, details, structures, embodiments, and / or methods in accordance with the present disclosure, are intended to convey that the described components, features, details, structures, embodiments, and / or methods are illustrative, non-exclusive examples of the components, features, details, structures, embodiments, and / or methods in accordance with the present disclosure. Thus, the described components, features, details, structures, embodiments, and / or methods are not intended to be restrictive, required, or exclusive / exhaustive; and other components, features, details, structures, embodiments, and / or methods, including components, features, details, structures, embodiments, and / or methods that are structurally and / or functionally similar and / or equivalent, are also within the scope of the present disclosure.

[0116] As used herein, when modifying a degree or relationship, "at least substantially" can include not only the stated "substantially" degree or relationship, but also the entire degree of the stated degree or relationship. A substantial amount of the degree or relationship can include at least 75% of the degree or relationship. For example, an object that is at least substantially formed of a material includes an object in which at least 75% of the object is formed of the material, and also includes an object that is entirely formed of the material. As another example, a first length that is at least substantially as long as a second length includes a first length that is within 75% of the second length, and also includes a first length that is as long as the second length.

[0117] Illustrative, non-exclusive examples of a safety brake assembly, a circular saw, and a method in accordance with the present disclosure are given in the paragraphs listed below. Within the scope of the present disclosure, the various steps of the methods described herein (including those in the paragraphs listed below) may additionally or alternatively be referred to as "steps" for performing the recited actions.

[0118] A1. A safety brake adapted for a circular saw, the safety brake comprising:

[0119] A sensor assembly configured to detect an actuation parameter and generate a trigger signal in response to detecting the actuation parameter;

[0120] A brake assembly, the brake assembly including a brake cam configured to selectively transition between a disengaged configuration and an engaged configuration, in the disengaged configuration, the brake cam being spaced apart from a saw blade receiving area of the safety brake, wherein the saw blade receiving area is configured to receive a circular saw blade, and in the engaged configuration, the brake cam extending into the saw blade receiving area and being configured to operatively engage a flat side surface of the circular saw blade and thereby resist rotation of the circular saw blade; and

[0121] An actuator assembly configured to selectively transition the brake cam from the disengaged configuration to the engaged configuration in response to receiving the trigger signal from the sensor assembly.

[0122] A1.1 The safety brake according to paragraph A1, wherein the actuation parameter includes an undesired event parameter indicating an undesired event to be avoided using the circular saw.

[0123] A1.2 The safety brake according to any one of paragraphs A1 - A1.1, wherein the actuation parameter includes a kickback parameter indicating the likelihood of kickback of the circular saw.

[0124] A1.3 The safety brake according to any one of paragraphs A1 - A1.2, wherein the actuation parameter includes a movement parameter indicating an undesired movement of the circular saw.

[0125] A1.4 The safety brake according to any one of paragraphs A1 - A1.3, wherein the actuation parameter includes a proximity parameter indicating that the distance between an individual and the circular saw blade is less than a threshold distance.

[0126] A1.4.1 The safety brake according to paragraph A1.4, wherein the threshold distance is one of less than 5 millimeters (mm), less than 4 mm, less than 3 mm, less than 2 mm, less than 1 mm, or less than 0.5 mm.

[0127] A1.4.2 The safety brake according to any one of paragraphs A1.4 to A1.4.1, wherein the threshold distance includes contact between the individual and the circular saw blade.

[0128] A2. The safety brake according to any one of paragraphs A1 - A1.4.2, wherein the brake assembly is a non - destructive brake assembly configured to selectively stop rotation of the circular saw blade.

[0129] A3. The safety brake according to any one of paragraphs A1 - A2, wherein the brake assembly is a resetable brake assembly configured to selectively and repeatedly switch between the disengaged configuration and the engaged configuration.

[0130] A4. The safety brake according to any one of paragraphs A1 - A3, wherein the brake assembly is configured to resist the rotation of the circular saw blade in at least one of the following cases:

[0131] (i) Without damaging the circular saw blade; and

[0132] (ii) Without damaging the brake assembly.

[0133] A5. The safety brake according to any one of paragraphs A1 - A4, wherein when in the engaged configuration, the brake cam is at least one of the following:

[0134] (i) Not engaged with the teeth of the circular saw blade; and

[0135] (ii) Spaced apart from the teeth of the circular saw blade.

[0136] A6. The safety brake according to any one of paragraphs A1 - A5, wherein the brake cam is configured to rotate about a cam rotation axis to selectively switch between the disengaged configuration and the engaged configuration.

[0137] A7. The safety brake according to paragraph A6, wherein the saw blade receiving area is a flat or at least substantially flat saw blade receiving area, and further wherein the cam rotation axis is parallel to or at least substantially parallel to the flat saw blade receiving area.

[0138] A8. The safety brake according to any one of paragraphs A1 - A7, wherein the brake cam includes a cam biasing mechanism that biases the brake cam toward the disengaged configuration.

[0139] A9. The safety brake according to paragraph A8, wherein the cam biasing mechanism includes at least one of the following:

[0140] (i) An elastic cam biasing mechanism;

[0141] (ii) A cam biasing spring; and

[0142] (iii) A cam biasing torsion spring.

[0143] A10. The safety brake according to any one of paragraphs A1 - A9, wherein the braking cam defines a saw blade engaging surface configured to operatively engage a flat side surface of a circular saw blade.

[0144] A11. The safety brake according to paragraph A10, wherein the saw blade engaging surface is shaped such that when the braking cam is switched from the disengaged configuration to the engaged configuration, the braking cam presses more strongly against the circular saw blade gradually.

[0145] A12. The safety brake according to any one of paragraphs A10 - A11, wherein the saw blade engaging surface defines an eccentric profile.

[0146] A13. The safety brake according to any one of paragraphs A10 - A12, wherein the saw blade engaging surface defines a logarithmic spiral profile.

[0147] A13.1. The safety brake according to any one of paragraphs A10 - A13, wherein the saw blade engaging surface defines a region where the radius optionally increases relative to the cam rotation axis of the braking cam, and a region where the radius is optionally constant relative to the cam rotation axis of the braking cam.

[0148] A13.2. The safety brake according to paragraph A13, wherein the braking cam is configured to start operatively engaging the circular saw blade with the region where the radius increases, and then operatively engage the circular saw blade with the region where the radius is constant.

[0149] A14. The safety brake according to any one of paragraphs A10 - A13.2, wherein the saw blade engaging surface includes a cam friction material selected to increase the coefficient of friction between the saw blade engaging surface and the circular saw blade.

[0150] A15. The safety brake according to paragraph A14, wherein the cam friction material includes at least one of the following:

[0151] (i) Diamond coating;

[0152] (ii) Abrasive material;

[0153] (iii) Abrasive grain coating;

[0154] (iv) Ceramic material;

[0155] (iv) Sintered material; and

[0156] (v) Metal alloy.

[0157] A16. The safety brake according to any one of paragraphs A10 - A15, wherein the brake cam includes a saw blade engagement surface insert that is operatively attached to the remainder of the brake cam and defines the saw blade engagement surface.

[0158] A17. The safety brake according to any one of paragraphs A10 - A16, wherein the saw blade engagement surface is integral with the brake cam.

[0159] A18. The safety brake according to any one of paragraphs A10 - A17, wherein the saw blade engagement surface is at least one of being applied to the brake cam and coating the brake cam.

[0160] A19. The safety brake according to any one of paragraphs A1 - A18, wherein after transitioning from the disengaged configuration to the engaged configuration, the brake cam is shaped to remain in the engaged configuration, optionally until the brake cam is released from the engaged configuration by a user of the circular saw.

[0161] A20. The safety brake according to paragraph A19, wherein the operative engagement between the circular saw blade and the brake cam holds the brake cam in the engaged configuration.

[0162] A21. The safety brake according to any one of paragraphs A1 - A20, wherein the brake assembly includes a stop configured to limit rotation of the brake cam.

[0163] A22. The safety brake according to paragraph A21, wherein the stop includes a disengaged configuration stop configured to limit rotation of the brake cam away from the saw blade receiving area when the brake cam is in the disengaged configuration.

[0164] A23. The safety brake according to any one of paragraphs A21 - A22, wherein the stop includes an engaged configuration stop configured to limit rotation of the brake cam toward the saw blade receiving area when the brake cam is in the engaged configuration.

[0165] A24. The safety brake according to any one of paragraphs A21 - A23, wherein the stop is at least partially defined by the brake cam.

[0166] A24.1 The safety brake according to any one of paragraphs A21 - A24, wherein the stop is different from the brake cam and is configured to operatively engage with the brake cam to limit rotation of the brake cam.

[0167] A25. The safety brake according to any one of paragraphs A1 - A24.1, wherein the brake assembly further includes a housing configured to operatively support the brake cam and the actuator assembly.

[0168] A26. The safety brake according to paragraph A25, wherein the housing at least partially surrounds the saw blade receiving area.

[0169] A27. The safety brake according to any one of paragraphs A25 - A26, wherein the housing includes a split housing configured to be disassembled into at least two housing regions.

[0170] A28. The safety brake according to any one of paragraphs A1 - A27, wherein the brake assembly further includes a brake pad including pad friction material.

[0171] A29. The safety brake according to paragraph A28, wherein the brake pad is positioned relative to the brake cam such that the pad friction material faces the brake cam.

[0172] A30. The safety brake according to any one of paragraphs A28 - A29, wherein the brake pad is positioned relative to the brake cam such that the saw blade receiving area at least partially extends between the brake pad and the brake cam.

[0173] A31. The safety brake according to any one of paragraphs A28 - A30, wherein the brake pad includes an adjustment mechanism configured to selectively adjust the distance between the brake pad and the brake cam.

[0174] A32. The safety brake according to any one of paragraphs A28 - A31, wherein the flat side surface of the circular saw blade is the first flat side surface of the circular saw blade, wherein the circular saw blade includes a second flat side surface opposite the first flat side surface, and further wherein the pad friction material is configured to operatively engage the second flat side surface of the circular saw blade.

[0175] A33. The safety brake according to any one of paragraphs A28 - A32, wherein the brake assembly is configured such that when the brake cam is in the engaged configuration, the saw blade is pressed between the brake pad and the brake cam.

[0176] A33.1. The safety brake according to any one of paragraphs A28 - A33, wherein the brake pad includes a pivotable pad mount configured to allow the brake pad to rotate restrictedly about at least one of the following:

[0177] (i) about at least one pivot axis; and

[0178] (ii) about a pivot point.

[0179] A33.2. The safety brake according to paragraph A33.1, wherein the pivot pad mount is configured to allow limited rotation of the brake pad about a plurality of pivot axes.

[0180] A33.3. The safety brake according to any one of paragraphs A33.1 - A33.2, wherein the pivot pad mount includes a concave mounting member and a convex mounting member, the concave mounting member defining a concave recessed area, the convex mounting member being shaped to be received within the concave recessed area, and further wherein the pivot pad mount is configured to allow limited rotation of the brake pad via relative movement between the concave mounting member and the convex mounting member.

[0181] A33.4. The safety brake according to paragraph A33.3, wherein the pivot pad mount further includes a mounting fastener that operably attaches the concave mounting member and the convex mounting member to each other.

[0182] A33.5. The safety brake according to paragraph A33.4, wherein the concave mounting member includes a hole, and further wherein the mounting fastener extends through the hole.

[0183] A33.6. The safety brake according to any one of paragraphs A33.1 - A33, wherein the pivot point is at least one of the following:

[0184] (i) spaced from the friction surface of the brake pad; and

[0185] (ii) coplanar with the friction surface of the brake pad.

[0186] A33.7. The safety brake according to any one of paragraphs A33.1 - A33.6, wherein the brake pad is operably attached to the remainder of the safety brake via the pivot pad mount.

[0187] A34. The safety brake according to any one of paragraphs A1 - A33.7, wherein the safety brake further includes an attachment mechanism configured to operably attach at least a portion of the safety brake to a circular saw.

[0188] A35. The safety brake according to paragraph A34, wherein the attachment mechanism includes a floating attachment mechanism configured to allow the saw blade receiving area to be operably translated relative to the remainder of the circular saw, optionally along a floating axis that is at least substantially perpendicular to the flat side surface of the circular saw blade.

[0189] A36. The safety brake according to paragraph A35, wherein the floating attachment mechanism includes an attachment pin, and further wherein the attachment mechanism is configured to allow the saw blade receiving area to be operably translated relative to the remainder of the circular saw and along the longitudinal axis of the attachment pin.

[0190] A36.1. The safety brake according to any one of paragraphs A35 - A36, wherein the floating attachment mechanism includes a floating attachment mechanism lock configured to selectively allow and selectively restrict the operable translation of the saw blade receiving area relative to the remainder of the circular saw.

[0191] A37. The safety brake according to any one of paragraphs A1 - A36.1, wherein the actuator assembly is an electric actuator assembly.

[0192] A38. The safety brake according to any one of paragraphs A1 - A37, wherein the actuator assembly includes a power source configured to supply power to the actuator assembly, optionally wherein the power source includes a capacitor.

[0193] A39. The safety brake according to any one of paragraphs A1 - A38, wherein the actuator assembly includes an actuator arm configured to selectively convert the brake cam from the disengaged configuration to the engaged configuration.

[0194] A40. The safety brake according to any one of paragraphs A1 - A39, wherein the actuator assembly includes an electromagnet configured to selectively convert the brake cam from the disengaged configuration to the engaged configuration.

[0195] A41. The safety brake according to any one of paragraphs A1 - A40, wherein the actuator assembly includes an actuator solenoid including a solenoid armature, wherein the solenoid armature is configured to operably engage the brake cam to convert the brake cam from the disengaged configuration to the engaged configuration.

[0196] A42. The safety brake according to paragraph A41, wherein when the actuator assembly converts the brake cam from the disengaged configuration to the engaged configuration, the solenoid armature is in direct physical contact with the brake cam.

[0197] A safety brake according to any one of paragraphs A1 - A42, wherein the actuator assembly includes at least one of the following:

[0198] (i) A shape memory alloy actuator assembly;

[0199] (ii) A reluctance actuator assembly;

[0200] (iii) A pneumatic actuator assembly;

[0201] (iv) A hydraulic actuator assembly;

[0202] (v) An explosive actuator assembly;

[0203] (vi) A piezoelectric actuator assembly;

[0204] (vii) A thermal actuator assembly;

[0205] (viii) A permanent magnet actuator assembly;

[0206] (ix) An electroactive polymer actuator assembly;

[0207] (x) An elastic biasing mechanism; and

[0208] (xi) An elastic biasing mechanism combined with a release mechanism.

[0209] A43.1. A safety brake according to any one of paragraphs A1 - A43, wherein the actuator assembly includes an actuator assembly biasing mechanism and a release mechanism, wherein the release mechanism is configured to selectively allow the actuator assembly biasing mechanism to convert the brake cam from a disengaged configuration to an engaged configuration in response to receiving a trigger signal.

[0210] A43.2. A safety brake according to paragraph A43.1, wherein the actuator assembly biasing mechanism includes at least one of the following:

[0211] (i) An elastic biasing mechanism; and

[0212] (ii) A spring.

[0213] A44. A safety brake according to any one of paragraphs A1.4 - A43.2, wherein the sensor assembly includes a proximity sensor configured to detect a proximity parameter.

[0214] A45. A safety brake according to any one of paragraphs A1 - A44, wherein the sensor assembly includes a capacitive sensor assembly configured to detect an actuation parameter.

[0215] A46. The safety brake according to any one of paragraphs A1 - A45, wherein the safety brake further includes a deflection mitigation structure configured to resist deflection of the saw blade into contact with the brake cam when the circular saw is used to cut a workpiece and the brake cam is in the disengaged configuration.

[0216] A47. The safety brake according to paragraph A46, wherein the deflection mitigation structure at least partially defines the saw blade receiving area.

[0217] A48. The safety brake according to any one of paragraphs A46 - A47, wherein the deflection mitigation structure includes a deflection mitigation surface configured to operably contact the circular saw blade when the circular saw blade deflects toward the brake cam to resist deflection of the saw blade into contact with the brake cam.

[0218] A49. The safety brake according to paragraph A48, wherein the deflection mitigation structure includes an electrical insulation structure configured to electrically insulate the deflection mitigation surface from the remainder of the safety brake.

[0219] A49.1. The safety brake according to paragraph A49, wherein the deflection mitigation structure is defined by an electrically insulating material and defines the deflection mitigation surface.

[0220] A49.2. The safety brake according to any one of paragraphs A49 - A49.1, wherein the electrical insulation structure includes an electrical insulation spacer that electrically isolates the deflection mitigation surface from the remainder of the safety brake.

[0221] A49.3. The safety brake according to paragraph A49, wherein the electrical insulation structure is formed of a ceramic material.

[0222] A50. The safety brake according to any one of paragraphs A1 - A49, wherein the safety brake further includes a reset mechanism configured to or allowing a user of the circular saw to selectively convert the brake cam from the engaged configuration to the disengaged configuration.

[0223] A51. The safety brake according to paragraph A50, wherein the reset mechanism includes an eccentric structure configured to operably translate the brake cam away from the saw blade receiving area.

[0224] A52. The safety brake according to any one of paragraphs A50 - A51, wherein the reset mechanism includes a pressure - actuated reset mechanism configured as at least one of the following:

[0225] (i) operably translate the braking cam away from the saw blade receiving area; and

[0226] (ii) operably translate the brake pad of the brake assembly away from the saw blade receiving area.

[0227] A52.1. The safety brake according to any one of paragraphs A50 - A52, wherein the reset mechanism includes a cam rotation structure configured to selectively rotate the braking cam away from the circular saw blade.

[0228] A52.2. The safety brake according to paragraph A52.1, wherein the cam rotation structure includes a cam rotation tool configured to selectively engage with the braking cam to rotate the braking cam away from the circular saw blade.

[0229] A52.3. The safety brake according to any one of paragraphs A52.1 - A52.2, wherein the cam rotation structure includes a pre - tensioned rod.

[0230] A53. The safety brake according to any one of paragraphs A1 - A52, wherein the brake assembly is configured to convert the braking cam from the disengaged configuration to the engaged configuration in at least one of the following:

[0231] (i) at least 0.1 millisecond (ms), at least 0.5 ms, at least 1 ms, at least 2 ms, at least 3 ms, at least 4 ms, or at least 5 ms; and

[0232] (ii) at most 10 ms, at most 9 ms, at most 8 ms, at most 7 ms, at most 6 ms, at most 5 ms, at most 4 ms, at most 3 ms, or at most 2 ms.

[0233] A54. The safety brake according to any one of paragraphs A1 - A53, wherein the safety brake further includes an interlock assembly configured to:

[0234] (i) allow current to be supplied to the motor of the circular saw when the safety brake is configured to selectively resist the rotation of the circular saw blade; and

[0235] (ii) prevent current from being supplied to the motor of the circular saw when at least one component of the safety brake is not configured to selectively resist the rotation of the circular saw blade.

[0236] A55. The safety brake according to paragraph A54, wherein the interlock assembly includes at least one of the following:

[0237] (i) A sensor status detector configured to indicate the status of the sensor assembly;

[0238] (ii) A brake assembly status detector configured to indicate the status of the brake assembly; and

[0239] (iii) An actuator assembly status detector configured to indicate the status of the actuator assembly.

[0240] A56. The safety brake according to any one of paragraphs A1 - A55, wherein there is no pivot link between the brake cam and the actuator assembly in the safety brake.

[0241] A57. The safety brake according to any one of paragraphs A1 - A56, wherein the cam rotation axis of the brake cam is perpendicular to or at least substantially perpendicular to the actuation axis of the actuator assembly.

[0242] A58. The safety brake according to any one of paragraphs A1 - A57, wherein the brake assembly includes a single brake cam.

[0243] A59. The safety brake according to any one of paragraphs A1 - A58, wherein the brake assembly is a locking brake assembly configured to remain in the engaged configuration once the brake cam is operably engaged with the circular saw blade.

[0244] B1. A circular saw, comprising:

[0245] A motor including a motor shaft configured to rotate about an axis of rotation;

[0246] An arbor operably attached to the motor shaft;

[0247] The safety brake according to any one of paragraphs A1 - A59; and

[0248] A circular saw blade, wherein the circular saw blade is operably attached to the circular saw via the arbor and extends at least partially within the saw blade receiving area of the brake assembly.

[0249] B2. The circular saw according to paragraph B1, wherein the motor includes an electric motor.

[0250] B3. The circular saw according to any one of paragraphs B1 - B2, wherein the arbor is configured to facilitate selective and repeated separation of the circular saw blade from the remainder of the circular saw.

[0251] B4. The circular saw according to any one of paragraphs B1 - B3, wherein the central axis comprises a threaded mandrel.

[0252] B5. The circular saw according to any one of paragraphs B1 - B4, wherein the circular saw further comprises a gripping area configured to be gripped by a user of the circular saw.

[0253] B6. The circular saw according to any one of paragraphs B1 - B5, wherein the circular saw further comprises a switch configured to selectively apply an electric current to the motor to provide motive power for rotation of the motor shaft.

[0254] B7. The circular saw according to any one of paragraphs B1 - B6, wherein the circular saw further comprises a saw blade guard configured to prevent contact between the user and the saw blade.

[0255] B8. The circular saw according to paragraph B7, wherein the saw blade guard comprises a retractable area configured to retract when the circular saw is used to cut a workpiece.

[0256] B9. The circular saw according to any one of paragraphs B7 - B8, wherein at least one area of the saw blade guard is defined by a safety brake.

[0257] B10. The circular saw according to any one of paragraphs B1 - B9, wherein the circular saw further comprises a workpiece support configured to support the workpiece when the workpiece is cut by the circular saw.

[0258] B11. The circular saw according to any one of paragraphs B1 - B10, wherein the circular saw further comprises at least one of the following:

[0259] (i) A power cord configured to supply an electric current to the circular saw; and

[0260] (ii) A battery configured to supply an electric current to the circular saw.

[0261] B12. The circular saw according to any one of paragraphs B1 - B11, wherein the circular saw comprises at least one of the following:

[0262] (i) A hand-held circular saw;

[0263] (ii) A miter saw;

[0264] (iii) A radial arm saw;

[0265] (iv) A table saw;

[0266] (v) A cutoff saw;

[0267] (vi) A plunge saw;

[0268] (vii) Orbital saw;

[0269] (viii) Up-cut saw; and

[0270] (ix) Panel saw.

[0271] B13. A circular saw according to any one of paragraphs B1 - B12, wherein the circular saw further comprises a clutch configured to reduce the likelihood of damage to at least one component of the circular saw when a safety brake is switched from a disengaged configuration to an engaged configuration to stop the rotation of the circular saw blade.

[0272] B14. The circular saw according to paragraph B13, wherein a central shaft at least partially defines the clutch.

[0273] B15. The circular saw according to any one of paragraphs B13 - B14, wherein the clutch is configured to:

[0274] (i) selectively permit relative rotation between the circular saw blade and the motor shaft when the torque between the circular saw blade and the motor shaft exceeds a threshold torque; and

[0275] (ii) resist relative rotation between the circular saw blade and the motor shaft when the torque between the circular saw blade and the motor shaft is less than the threshold torque.

[0276] B16. The circular saw according to any one of paragraphs B1 - B15, wherein the circular saw further comprises a saw blade isolation structure configured to electrically isolate the circular saw blade from at least one other component of the circular saw.

[0277] C1. A method of operating a circular saw, the method comprising:

[0278] causing a circular saw blade of the circular saw to rotate;

[0279] using a sensor assembly of the circular saw to detect that a distance between an individual and the circular saw blade is less than a threshold distance; and

[0280] in response to the detection, using a brake assembly of the circular saw to stop the rotation of the circular saw blade, wherein the brake assembly includes a brake cam, and further wherein the stopping includes causing a flat side surface of the circular saw blade to operably engage with the brake cam to stop the rotation of the circular saw blade.

[0281] C2. The method according to paragraph C1, wherein after the stopping, the method further comprises maintaining the operable engagement of the brake cam with the circular saw blade before actuating a reset mechanism of the circular saw.

[0282] C3. The method according to any one of paragraphs C1 - C2, wherein the method further comprises disengaging the brake cam from the circular saw blade.

[0283] C3.1. The method according to paragraph C3, wherein the disengaging comprises disengaging to proceed to at least one of the following:

[0284] (i) Permitting subsequent rotation of the circular saw blade;

[0285] (ii) Permitting reuse of the circular saw blade;

[0286] (iii) Permitting reuse of the brake assembly; and

[0287] (iv) Resetting the circular saw.

[0288] C3.2. The method according to any one of paragraphs C3 - C3.1, wherein after the disengaging, the method further comprises repeating at least the rotation.

[0289] C3.3. The method according to paragraph C3.2, wherein repeating the rotation comprises repeating the rotation without replacing the circular saw blade and without replacing the brake cam.

[0290] C4. The method according to paragraph C3, wherein disengaging the brake cam comprises disengaging by at least one of the following:

[0291] (i) Not removing the circular saw blade from the circular saw;

[0292] (ii) Not removing the brake assembly from the circular saw;

[0293] (iii) Not damaging the circular saw blade; and

[0294] (iv) Not damaging the brake assembly.

[0295] C5. The method according to any one of paragraphs C1 - C4, wherein the stopping comprises directly engaging the solenoid armature of the solenoid of the brake assembly with the brake cam.

[0296] C6. The method according to any one of paragraphs C1 - C5, wherein the stopping comprises rotating the brake cam about a cam rotation axis that is perpendicular or at least substantially perpendicular to the actuation axis of the actuator assembly of the brake assembly.

[0297] C6.1. The method according to any one of paragraphs C1 - C6, wherein the stopping comprises pressing the circular saw blade between the brake cam and the brake lining of the brake assembly.

[0298] C6.2. The method according to paragraph C6.1, wherein the stopping further includes pivoting the friction surface of the brake pad relative to the flat side surface of the circular saw blade during pressing.

[0299] C6.3. The method according to any one of paragraphs C6.1 to C6.2, wherein during the stopping, the method further includes centering the circular saw blade between the brake cam and the brake pad.

[0300] C6.4. The method according to any one of paragraphs C1 - C6.3, wherein before the rotation, the method further includes adjusting the distance between the brake cam and the circular saw blade by means of the floating attachment mechanism of the circular saw.

[0301] C6.5. The method according to any one of paragraphs C1 - C6.4, wherein the stopping includes pushing the brake cam into contact with the flat side surface of the circular saw blade by means of the actuator assembly biasing mechanism of the brake assembly.

[0302] C6.6. The method according to paragraph C6.5, wherein before the pushing, the stopping further includes releasing the brake cam by means of a release mechanism, and wherein the pushing is in response to the release.

[0303] C7. The method according to any one of paragraphs C1 - C6.6, wherein the brake assembly includes any suitable structure of any safety brake described in any one of paragraphs A1 - A59.

[0304] C8. The method according to any one of paragraphs C1 - C7, wherein the circular saw includes any suitable structure of any circular saw described in any one of paragraphs B1 - B16.

[0305] D1. Use of a brake assembly in a circular saw, the brake assembly including a brake cam for selectively resisting the rotation of a circular saw blade.

[0306] D2. Use of a brake cam in a circular saw for selectively stopping the circular saw blade of the circular saw.

[0307] D3. Use of a reset mechanism in a circular saw, the reset mechanism for selectively allowing the rotation of the circular saw blade of the circular saw after stopping the rotation of the circular saw blade by means of the brake assembly of the circular saw.

[0308] D4. Use of an actuator assembly in a circular saw, the actuator assembly directly contacting the brake cam to convert the brake cam from a disengaged configuration to an engaged configuration, in the disengaged configuration, the brake cam is spaced apart from the circular saw blade of the circular saw, and in the engaged configuration, the brake cam operably engages the circular saw blade and resists the rotation of the circular saw blade.

[0309] Use of any safety brake as described in any one of paragraphs A1 - A59 or any circular saw as described in any one of paragraphs B1 - B16 in combination with any method as described in any one of paragraphs C1 - C8.

[0310] D6. Use of any method as described in any one of paragraphs C1 - C8 in combination with any safety brake as described in any one of paragraphs A1 - A59 or any circular saw as described in any one of paragraphs B1 - B16.

[0311] Industrial Applicability

[0312] The safety brake assembly, circular saw, and method disclosed herein are applicable to the power tool industry.

[0313] It is believed that the present disclosure set forth above covers multiple independent inventions that can be used independently. Although each of these inventions has been disclosed in its preferred form, the specific embodiments disclosed and illustrated herein should not be considered limiting, as many variations are possible. The subject matter of the present invention includes all novel and non - obvious combinations and sub - combinations of the various elements, features, functions, and / or characteristics disclosed herein. Similarly, where a claim recites "a" or "first" element or its equivalent, such a claim should be understood to cover a combination of one or more such elements, neither requiring nor precluding a combination of two or more such elements.

[0314] It is believed that the following claims particularly point out certain combinations and sub - combinations of one of the disclosed inventions, and these combinations and sub - combinations are novel and non - obvious. Inventions embodied in other combinations and sub - combinations of features, functions, elements, and / or characteristics may be claimed by amendment of the present claims or presentation of new claims in this application or a related application. These amended or new claims, whether directed to different inventions or the same invention, whether different in scope, broader, narrower, or equivalent to the original claims, are also considered to be included within the subject matter of the inventions disclosed herein.

Claims

1. A safety brake adapted for a circular saw, the safety brake comprising: a sensor assembly configured to detect an actuation parameter and generate a trigger signal in response to detecting the actuation parameter; a brake assembly, the brake assembly comprising: (i) a brake cam configured to selectively transition between a disengaged configuration and an engaged configuration, in the disengaged configuration, the brake cam is spaced apart from a saw blade receiving area of the safety brake, wherein the saw blade receiving area is configured to receive a circular saw blade, and in the engaged configuration, the brake cam extends into the saw blade receiving area and is configured to operably engage a flat side surface of the circular saw blade and thereby resist rotation of the circular saw blade; and (ii) a brake pad comprising a pad friction material, wherein the brake pad is positioned relative to the brake cam such that the pad friction material faces the brake cam; and an actuator assembly configured to selectively transition the brake cam from the disengaged configuration to the engaged configuration in response to receiving the trigger signal from the sensor assembly, wherein there is no pivot link between the brake cam and the actuator assembly in the safety brake.

2. The safety brake according to claim 1, characterized in that, The brake assembly is a resetable brake assembly configured to selectively and repeatedly transition between the disengaged configuration and the engaged configuration.

3. The safety brake according to any one of claims 1-2, characterized in that The brake assembly is configured to resist rotation of the circular saw blade and satisfy at least one of the following: (i) not damage the circular saw blade; and (ii) not damage the brake assembly.

4. The safety brake according to any one of claims 1-2, characterized in that, When in the engaged configuration, the brake cam is at least one of the following: (i) not engage the teeth of the circular saw blade; and (ii) spaced apart from the teeth of the circular saw blade.

5. The safety brake according to any one of claims 1-2, characterized in that The brake cam is configured to rotate about a cam rotation axis to selectively transition between the disengaged configuration and the engaged configuration, wherein the saw blade receiving area is a flat saw blade receiving area, and further wherein the cam rotation axis is parallel to the flat saw blade receiving area.

6. The safety brake according to any one of claims 1-2, characterized in that, The cam rotation axis of the brake cam is perpendicular to the actuation axis of the actuator assembly.

7. The safety brake according to any one of claims 1-2, characterized in that, The brake cam includes a cam biasing mechanism that biases the brake cam toward the disengaged configuration.

8. The safety brake according to any one of claims 1-2, characterized in that, The brake cam defines a saw blade engagement surface configured to operably engage the flat side surface of the circular saw blade.

9. The safety brake according to claim 8, characterized in that, The saw blade engagement surface is shaped such that when the brake cam transitions from the disengaged configuration to the engaged configuration, the brake cam presses more strongly against the circular saw blade gradually.

10. The safety brake according to claim 8, characterized in that, The saw blade engagement surface defines a region of increasing radius and a region of constant radius, wherein the brake cam is configured to initially operably engage the circular saw blade with the region of increasing radius and subsequently operably engage the circular saw blade with the region of constant radius.

11. The safety brake according to any one of claims 1-2, characterized in that, After transitioning from the disengaged configuration to the engaged configuration, the brake cam is shaped to remain in the engaged configuration until released from the engaged configuration by the user of the circular saw.

12. The safety brake according to any one of claims 1-2, characterized in that, The brake assembly includes a stop configured to limit rotation of the brake cam.

13. The safety brake according to claim 12, wherein, The stop is distinct from the brake cam and is configured to operably engage the brake cam to limit rotation of the brake cam.

14. The safety brake according to any one of claims 1-2, characterized in that, The brake pad is positioned relative to the brake cam such that the saw blade receiving area extends at least partially between the brake pad and the brake cam.

15. The safety brake according to any one of claims 1-2, characterized in that, The brake assembly is configured such that when the brake cam is in the engaged configuration, the saw blade is clamped between the brake pad and the brake cam.

16. The safety brake according to any one of claims 1-2, characterized in that, The brake pad includes a pivotable pad mount configured to allow the brake pad to rotate restrictedly about at least one of: (i) at least one pivot axis; and (ii) a pivot point.

17. The safety brake according to claim 16, characterized in that, The pivotable pad mount includes a concave mounting member and a convex mounting member, the concave mounting member defining a concave recessed area, the convex mounting member shaped to be received within the concave recessed area, and further wherein the pivotable pad mount is configured to allow the brake pad to rotate restrictedly via relative movement between the concave mounting member and the convex mounting member.

18. The safety brake according to any one of claims 1-2, characterized in that, The safety brake further includes an attachment mechanism configured to operably attach at least a portion of the safety brake to the circular saw, wherein the attachment mechanism includes a floating attachment mechanism configured to allow the saw blade receiving area to translate operably relative to the remainder of the circular saw.

19. The safety brake according to any one of claims 1-2, characterized in that, The actuator assembly is an electric actuator assembly.

20. The safety brake according to any one of claims 1-2, characterized in that, The actuator assembly includes an actuator solenoid including a solenoid armature, wherein the solenoid armature is configured to operably engage the brake cam to transition the brake cam from the disengaged configuration to the engaged configuration.

21. The safety brake according to claim 20, characterized in that, When the actuator assembly transitions the brake cam from the disengaged configuration to the engaged configuration, the solenoid armature makes direct physical contact with the brake cam.

22. The safety brake according to any one of claims 1-2, characterized in that, The actuator assembly includes an actuator assembly biasing mechanism and a release mechanism, wherein the release mechanism is configured to selectively allow the actuator assembly biasing mechanism to transition the brake cam from the disengaged configuration to the engaged configuration in response to receipt of the trigger signal.

23. The safety brake according to any one of claims 1-2, characterized in that, The safety brake further includes a deflection mitigation structure configured to resist deflection of the circular saw blade into contact with the brake cam when the circular saw is used to cut a workpiece and the brake cam is in the disengaged configuration.

24. The safety brake according to claim 23, wherein, The deflection mitigation structure includes a deflection mitigation surface configured to operably contact the circular saw blade when the circular saw blade deflects toward the brake cam to resist deflection of the circular saw blade into contact with the brake cam, and further wherein the deflection mitigation structure includes an electrical insulation structure configured to electrically insulate the deflection mitigation surface from the remainder of the safety brake.

25. The safety brake according to any one of claims 1-2, characterized in that, The safety brake further includes a reset mechanism configured to selectively convert the brake cam from the engaged configuration to the disengaged configuration.

26. The safety brake according to claim 25, characterized in that, The reset mechanism includes an eccentric structure configured to operably translate the brake cam away from the saw blade receiving area.

27. The safety brake according to claim 25, characterized in that, The reset mechanism includes a pressure-actuated reset mechanism configured to at least one of the following: (i) operably translate the brake cam away from the saw blade receiving area; and (ii) operably translate the brake pads of the brake assembly away from the saw blade receiving area.

28. The safety brake according to claim 25, wherein, The reset mechanism includes a cam rotation structure configured to selectively rotate the brake cam away from the circular saw blade.

29. The safety brake according to claim 28, characterized in that, The cam rotation structure includes a cam rotation tool configured to selectively engage the brake cam to rotate the brake cam away from the circular saw blade.

30. A circular saw, comprising: a motor including a motor shaft configured to rotate about an axis of rotation; a mandrel operably attached to the motor shaft; a safety brake according to any one of claims 1-29; and a circular saw blade, wherein the circular saw blade is operably attached to the circular saw via the mandrel and at least partially extends within the saw blade receiving area of the brake assembly.

31. The circular saw according to claim 30, characterized in that, The circular saw includes at least one of the following: (i) a hand-held circular saw; (ii) a miter saw; (i) a radial arm saw; (ii) a table saw; (iii) a cutoff saw; (iv) a plunge saw; (v) a track saw; (vi) an upcut saw; and (ix) a panel saw.

32. A method of operating a circular saw according to claim 30 or 31, the method comprising: rotating the circular saw blade of the circular saw; detecting, using a sensor assembly of the circular saw, that a distance between an individual and the circular saw blade is less than a threshold distance; and in response to the detection, stopping rotation of the circular saw blade using a brake assembly of the circular saw, wherein the stopping includes operably engaging a flat side surface of the circular saw blade with the brake cam and pressing the circular saw blade between the brake cam and the brake pads to stop rotation of the circular saw blade.

33. The method according to claim 32, wherein After the stopping, the method further includes maintaining the brake cam in operable engagement with the circular saw blade before actuating a reset mechanism of the circular saw.

34. The method according to claim 32 or 33, characterized in that The method further includes disengaging the brake cam from the circular saw blade to achieve at least one of the following: (i) Allow the circular saw blade to rotate subsequently; (ii) Allow the circular saw blade to be reused; (i) Allow the brake assembly to be reused; and (ii) Reset the circular saw.

35. The method according to claim 32 or 33, characterized in that, The stopping includes directly engaging the solenoid armature of the solenoid of the brake assembly with the brake cam.

36. The method according to claim 32 or 33, characterized in that, The stopping includes rotating the brake cam about a cam rotation axis that is perpendicular to the actuation axis of the actuator assembly of the brake assembly.

37. The method according to claim 32 or 33, characterized in that, The stopping includes using the biasing mechanism of the actuator assembly of the brake assembly to push the brake cam into contact with the flat side surface of the circular saw blade.

38. The method according to claim 37, characterized in that, Before the pushing, the stopping further includes releasing the brake cam using a release mechanism, wherein the pushing is responsive to the release.

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