A circular saw having a blade that moves relative to a fixed base structure during operation of the circular saw to cut a workpiece and a method of detecting kickback conditions of such a circular saw

Abstract

A circular saw having a blade that moves relative to a fixed base structure during operational use of the circular saw to cut a workpiece and a method of detecting kickback conditions of such a circular saw. The circular saw includes a base structure, a user-actuated assembly, an attachment structure, and a controller. The attachment structure is configured to allow constrained relative motion between the base structure and the user-actuated assembly in a direction of motion and during operational use of the circular saw to cut a workpiece. A motion sensor is configured to generate a motion signal indicative of motion of the user-actuated assembly along the direction of motion. The controller is programmed to initiate a kickback response of the circular saw in response to the motion signal indicative of a kickback condition of the circular saw.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 151,227, filed February 19, 2021, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to a circular saw having a blade that moves relative to a fixed base structure during operation of the circular saw cutting a workpiece, and a method for detecting the recoil condition of such a circular saw. Background Technology

[0004] Power tools (e.g., circular saws) may behave unpredictably under certain operating conditions, such as by rapidly accelerating in unexpected and / or unintended ways. This behavior may be referred to herein as a "kickback condition" of the power tool. As an example, when cutting a workpiece with a circular saw, the workpiece can extend along both lateral sides of the circular saw blade. If the workpiece is allowed to engage with and / or clamp the sides of the circular saw blade, the friction between the sides of the blade and the workpiece can power the saw's kickback. As another example, if the circular saw blade accidentally cuts deep into the workpiece and / or enters atypically hard or soft areas of the workpiece, the change in force acting on the circular saw may manifest as a kickback condition.

[0005] Mechanisms for detecting and responding to recoil have been developed. However, these mechanisms may be specific to a particular type or class of power tools and / or may not be effective in all power tools. For example, some circular saws have blades that rotate about a fixed axis relative to the base of the circular saw during operation. For such circular saws, recoil detection may primarily aim to prevent the workpiece from accelerating toward the user.

[0006] On the other hand, some circular saws have blades that rotate about an axis, which move relative to the fixed base structure of the circular saw during operation. As an example, the axis can be moved by translation and / or pivoting relative to the fixed base structure. For such circular saws, detecting recoil is desirable to limit or prevent accidental translation, pivoting, or other movement of the circular saw blade and the corresponding blade-mounted portion of the circular saw relative to and / or toward the user. Therefore, there is a need for improved circular saws with blades that move relative to the fixed base during operation of the circular saw cutting a workpiece, and / or improved methods for detecting recoil in such circular saws. Summary of the Invention

[0007] A circular saw having a blade that moves relative to a fixed base structure during operation of the circular saw cutting a workpiece, and a method for detecting the recoil of such a circular saw. The circular saw includes a base structure, a user actuation assembly, an attachment structure, and a controller. The base structure includes a saw support and a workpiece support. The user actuation assembly includes a motor, a spindle, and a motion sensor. The motor includes a motor shaft configured to rotate about an axis of rotation. The spindle is operatively attached to the motor shaft and configured to receive and rotate the circular saw blade in a plane of blade rotation. The user actuation assembly is operatively attached to the base structure via the attachment structure such that the workpiece support faces the user actuation assembly. The attachment structure is configured to allow constrained relative movement between the base structure and the user actuation assembly in the direction of motion and during operation of the circular saw cutting a workpiece. The motion sensor is configured to detect the movement of the user actuation assembly along the direction of motion and to generate a motion signal indicating the movement of the user actuation assembly along the direction of motion. The controller is programmed to receive motion signals and, in response to motion signals indicating the recoil status of the circular saw, initiate the recoil response of the circular saw.

[0008] The method includes rotating the circular saw blade in a plane of rotation of the blade. The method also includes applying an actuating force to a user actuation component of the circular saw, and in response to the application, moving the user actuation component relative to a base structure of the circular saw in a direction of motion. The method further includes detecting the movement of the user actuation component along the direction of motion using a motion sensor of the user actuation component, and initiating a recoil response of the circular saw in response to the movement of the user actuation component indicating a recoil condition of the circular saw. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of an example of a circular saw according to this disclosure.

[0010] Figure 2 This is a schematic diagram of an example of a circular saw according to this disclosure.

[0011] Figure 3 This is a schematic diagram of an example of a circular saw according to this disclosure.

[0012] Figure 4 This is a schematic diagram of an example of a circular saw according to this disclosure.

[0013] Figure 5 This is a less schematic illustration of an example of a circular saw based on this disclosure.

[0014] Figure 6 This is an illustration of an example of linear acceleration detected along a first linear detection axis during recoil, according to the present disclosure.

[0015] Figure 7This is an illustration of an example of linear acceleration detected along a second linear detection axis during recoil, according to the present disclosure.

[0016] Figure 8 This is an illustration of an example of the scalar sum of the absolute values ​​of linear accelerations detected along a first linear detection axis and the absolute values ​​of linear accelerations detected along a second linear detection axis, according to this disclosure.

[0017] Figure 9 This is a flowchart illustrating an example of a method for detecting the recoil condition of a circular saw including a circular saw blade, according to the present disclosure. Detailed Implementation

[0018] Figures 1 to 9 Examples of a circular saw 10 according to this disclosure, components of the circular saw 10, parameters that can be measured during operation and / or methods 200 of the circular saw 10 are provided. Figures 1 to 9 Each figure in the document uses the same numbers to label elements that have similar or at least substantially similar purposes, and these elements may be disregarded herein. Figures 1 to 9 Each of these is discussed in detail. Similarly, in Figures 1 to 9 Each element in the diagram may not be labeled, but for consistency, the associated reference numerals may be used herein. This document refers to... Figures 1 to 9 One or more of the elements, components and / or features discussed herein may be included without departing from the scope of this disclosure. Figures 1 to 9 Any one of the diagrams and / or with Figures 1 to 9 any one Figure 1 Start using it.

[0019] Typically, solid lines indicate elements that may be included in a particular embodiment, while dashed lines indicate optional elements. However, elements shown in solid lines may not be essential for all embodiments, and in some embodiments, may be omitted without departing from the scope of the invention.

[0020] Figures 1 to 4 This is a schematic diagram of an example of the circular saw 10 according to this disclosure. Figure 5 This is a simplified schematic diagram of an example of the circular saw 10 according to this disclosure. For example... Figures 1 to 5As shown, the circular saw 10 includes a base structure 20, an attachment structure 50, a user actuation assembly 100, and a controller 190. The base structure 20 includes a saw support 30 and a workpiece support 40, and the base structure 20 may additionally or alternatively be referred to herein as a fixed base structure 20. The user actuation assembly 100 is operatively attached to the base structure 20 via, through, and / or using the attachment structure 50. This attachment allows the workpiece support 40 to be described as facing the user actuation assembly 100 and / or configured to support the workpiece 90 between the workpiece support and the user actuation assembly. Additionally, the attachment structure 50 is configured to allow and / or facilitate limited and / or constrained relative movement between the base structure 20 and the user actuation assembly 100 in a direction of motion. This direction of motion may be along and / or around a motion axis 52 and may occur during the operation of the circular saw (i.e., during the cutting of the workpiece 90 using the circular saw). Examples of such relative movement include translational and / or pivoting movements. In other words, the relative movement between the base structure 20 and the user actuation assembly 100 along and / or around the axis of motion 52 can cause or be used to generate an operative engagement and / or physical contact between the circular saw blade 170 of the user actuation assembly 100 and the workpiece 90. This operative engagement can allow and / or facilitate the circular saw blade cutting the workpiece.

[0021] User actuation assembly 100 includes a motion sensor 110, a motor 150, and a spindle 160. Motor 150 includes a motor shaft 152 configured to rotate about an axis of rotation 154. Spindle 160 is operatively attached to motor shaft 152 and / or configured to receive a circular saw blade 170, transmit power from motor 150 to the circular saw blade, and / or rotate the circular saw blade in a plane of rotation, which may, for example, be parallel to... Figures 1 to 5 The XY plane and / or the axis of rotation 154 perpendicular to the axis. As discussed in more detail herein, the user actuation assembly 100 according to this disclosure is configured to move relative to the base structure 20, such as by translation and / or pivoting, during operational use of the circular saw cutting the workpiece 90. Such movement of the user actuation assembly 100 may also cause the circular saw blade 170 mounted on or otherwise received by the spindle 160 of the user actuation assembly to move relative to the base structure, such as by translation and / or pivoting, during operational use of the circular saw cutting the workpiece.

[0022] Motion sensor 110 is configured to detect movement of user-actuated component 100 along and / or about motion axis 52, such as at least one speed, rotational speed, rate, rotational speed, acceleration, and / or rotational acceleration. Motion sensor 110 may additionally or alternatively be configured to generate a motion signal 112 indicating movement of the user-actuated component along the direction of motion. Controller 190 is programmed to receive motion signal 112 and / or initiate a recoil response of circular saw 10 in response to a motion signal indicating recoil status.

[0023] During operation of the circular saw 10 cutting the workpiece 90, and as discussed in more detail herein, the circular saw 10 can be positioned such that the saw support 30 supports the circular saw, for example, on the ground, on a table, and / or on a shelf. Alternatively, during operation of the circular saw 10 cutting the workpiece 90, the base structure 20 and / or its saw support 30 can be fixed. Subsequently, rotational power can be applied to the circular saw blade 170 using the motor 150, for example, causing the circular saw blade to rotate in its plane of rotation and / or about an axis of rotation 154. At least partially simultaneously with this rotation, a user of the circular saw 10 can apply actuating force to the user actuation assembly 100 to cause the user actuation assembly to move in a direction of motion, for example, about and / or along at least one axis of motion 52.

[0024] In some examples, and as discussed in more detail herein, this actuation force can cause the user actuation assembly 100 to move relative to the base structure 20 along a motion axis 52 in the form of a linear motion axis 62, thereby allowing and / or facilitating contact and / or engagement between the circular saw blade 170 and the workpiece 90. In some examples, and also as discussed in more detail herein, this actuation force may cause the user actuation assembly 100 to rotate relative to the base structure 20 about a motion axis 52 in the form of a rotational motion axis 72, thereby allowing and / or facilitating contact and / or engagement between the circular saw blade 170 and the workpiece 90. Contact and / or engagement between the circular saw blade and the workpiece can cause the circular saw blade to cut the workpiece.

[0025] During the cutting of workpiece 90 by the circular saw blade 170, a recoil condition may occur. As used herein, the phrase "recoil condition" can refer to a situation where the circular saw or at least one area of ​​the circular saw (e.g., the user actuation component 100) moves or is caused to move in an unexpected and / or unpredictable manner during the operation of the circular saw cutting the workpiece. Such movement may include unexpected linear and / or rotational movement and / or acceleration of the circular saw area, and may startle the user of the circular saw, causing the user actuation component to accelerate relative to and / or toward the circular saw, and / or damage the workpiece.

[0026] However, as discussed in more detail herein, the controller 190 of the circular saw 10 can be configured to determine the presence of a recoil condition and / or to initiate a recoil response upon detection of a recoil condition and / or in response to a recoil condition. Also as discussed in more detail herein, the recoil response can reduce the likelihood of startling the user of the circular saw 10 according to this disclosure, decrease the magnitude of the motion and / or acceleration of the user-actuated components relative to and / or toward the user, and / or reduce the likelihood of damaging the workpiece compared to conventional circular saws that do not include the motion sensor 110 and / or controller 190 according to this disclosure.

[0027] The attachment structure 50 may include any suitable structure adapted, configured, designed, and / or constructed to operatively attach the user actuation component 100 to the base structure 20 and / or allow constrained relative movement between the user actuation component and the base structure in a direction of motion. As discussed, the direction of motion may be along and / or about the axis of motion 52. In some examples, the attachment structure 50 may be configured to allow constrained relative movement between the base structure 20 and the user actuation component 100 in response to receiving actuation force from a user of the circular saw.

[0028] In some examples, and as discussed, the direction of motion may include, or may include only, one or a single linear motion component, which may, for example, point along linear motion axis 62. Alternatively, the constrained relative motion between the base structure 20 and the user actuation component 100 may be along linear motion axis 62 or a single linear motion axis 62, and in some examples, only along linear motion axis 62 or a single linear motion axis 62. In other words, the linear and / or translational relative motion between the base structure 20 and the user actuation component 100 may be along linear motion axis 62 or a single linear motion axis 62, and in some examples, only along linear motion axis 62 or a single linear motion axis 62.

[0029] In examples of attachment structures 50 that allow and / or facilitate constrained linear motion along or only along the linear motion axis 62, the linear motion axis may extend parallel to or at least substantially parallel to the blade rotation plane of the circular saw blade 170. Additionally or alternatively, during operational use of the circular saw to cut a workpiece, the linear motion axis 62 may extend toward and / or away from the user. Therefore, any recoil movement of the user actuation assembly 100 along the linear motion axis 62 can be particularly startling to the user. Thus, it may be particularly advantageous that the circular saw 10 according to this disclosure is configured to respond to recoil conditions, for example, by mitigating or reducing such linear motion.

[0030] The attachment structure 50 may include any suitable structure adapted, configured, designed, and / or constructed to allow and / or facilitate finite linear movement of the user actuation component 100 relative to the base structure 20 along the linear motion axis 62. As an example, the attachment structure 50 may include a linear guide 60. Examples of linear guides 60 include tracks and shuttles, linear support assemblies, and / or guide rails. The linear guide 60 may be configured to allow and / or facilitate... Figure 1 , Figure 3 and Figure 5 The retraction orientation 64 shown is... Figure 2 and Figure 4 The finite linear motion between the extended orientations 66 shown is along the linear motion axis 62.

[0031] In an example of a circular saw 10 in which the attachment structure 50 allows and / or facilitates limited linear motion along the linear motion axis 62, the motion sensor 110 may include a linear detection axis 114 that coincides with or at least substantially coincides with the linear motion axis 62, such as... Figure 1 and Figure 2 As shown. In some such examples, the controller 190 can be programmed to initiate a recoil response if the motion signal 112 indicates that the linear acceleration along the linear detection axis 114 is greater than a threshold linear acceleration magnitude and / or when the motion signal 112 indicates that the linear acceleration along the linear detection axis 114 is greater than the threshold linear acceleration magnitude. The threshold linear acceleration magnitude can be selected or predetermined based on one or more of a number of factors, such as the type of circular saw, the size of the circular saw blade, the expected rotation speed of the circular saw blade during the operation of the circular saw, manufacturing considerations, manufacturer and / or operator preferences, etc. Figure 6 An example is shown of acceleration measured along the linear detection axis 114 over time during a recoil condition (indicated by 98). As shown therein, the recoil condition is clearly visible when the acceleration measured by the motion sensor increases significantly.

[0032] In some such examples, the motion sensor 110 may include a first linear detection axis 116 and a second linear detection axis 118. The first linear detection axis may be parallel to or at least substantially parallel to the linear motion axis 62, such as... Figure 1 and Figure 2 As shown in the diagram. The second linear detection axis may be perpendicular to or at least substantially perpendicular to the first linear detection axis, as... Figures 1 to 5 As shown in the diagram. Additionally or alternatively, the second linear detection axis may be aligned with or at least substantially aligned with gravity, as... Figure 1 and Figure 2 As shown in the image. Figure 6 The image shows the acceleration measured by motion sensor 110 along the first linear detection axis 116 during recoil condition 98, while... Figure 7The acceleration measured by motion sensor 110 along the second linear detection axis 118 during recoil condition 98 is shown. Again, the recoil condition is clearly visible due to the significant increase in acceleration measured by the motion sensor in both directions.

[0033] In some such examples, the controller 190 may be programmed to initiate a recoil response if the vector sum of the linear accelerations along the first linear detection axis 116 and the second linear detection axis 118, as indicated by the motion signal 112, is greater than a threshold linear acceleration magnitude and / or when the vector sum of the linear accelerations along the first linear detection axis 116 and the second linear detection axis 118, is greater than a threshold linear acceleration magnitude. In some such examples, the controller 190 may be programmed to initiate a recoil response if the scalar sum of the absolute values ​​of the linear accelerations along the first linear detection axis 116 and the second linear detection axis 118, as indicated by the motion signal 112, is greater than a threshold linear acceleration magnitude and / or when the scalar sum of the absolute values ​​of the linear accelerations along the first linear detection axis 116 and the second linear detection axis 118, as indicated by the motion signal 112, is greater than a threshold linear acceleration magnitude. Figure 8 An example of this scalar sum is illustrated. By... Figure 8 and Figure 6 and Figure 7 The comparison shows that the scalar significantly improves the signal-to-noise ratio for detecting recoil condition 98.

[0034] As discussed, controller 190 is also programmed to initiate a recoil response of the circular saw in response to a motion signal indicating a recoil condition. In some examples, controller 190 may be programmed to stop and / or dampen the movement of user actuation component 100 along linear motion axis 62 as a recoil response, for example, by reducing the movement and / or acceleration of user actuation component 100 toward the user during a recoil state, or by reducing the likelihood of movement and / or acceleration of user actuation component 100 toward the user during a recoil state. In some such examples, circular saw 10 may include a linear motion axis braking structure 68, which may be configured to selectively resist or stop the movement of user actuation component 100 along linear motion axis 62. In some such examples, controller 190 may be programmed to actuate linear motion axis braking structure 68 as a recoil response. Examples of linear motion axis braking structure 68 include any suitable damper, fluid damper, brake, brake pad, and / or friction enhancement device, which may be configured to stop and / or dampen the movement of user actuation component along linear motion axis. As an example, a damper or fluid damper may be coupled to the attachment structure 50 and the user actuation assembly 100. The controller 190 may be configured to close the valve of the damper or fluid damper to increase the resistance to or dampen the movement of the user actuation assembly 100 along the linear motion axis 62 as a recoil response. As another example, a brake pad may be arranged on the attachment structure 50 or the linear guide 60 along the linear motion axis 62, and a brake cam may be arranged on the user actuation assembly 100. The controller 190 may be configured to engage the brake cam with the brake pad as a recoil response.

[0035] In some instances, and as discussed in more detail herein, the direction of motion may include, or may include only, one or a single rotational motion component, which may, for example, be about a rotational motion axis 72. Alternatively, the constrained relative motion between the base structure 20 and the user actuation component 100 may be about a rotational motion axis 72 or a single rotational motion axis 72, and in some instances, only about a rotational motion axis 72 or a single rotational motion axis 72. Again, the rotational relative motion between the base structure 20 and the user actuation component 100 may be about a rotational motion axis 72 or a single rotational motion axis 72, and in some instances, only about a rotational motion axis 72 or a single rotational motion axis 72.

[0036] In an example of an attachment structure 50 that allows and / or facilitates constrained rotational movement about a rotational axis 72, the rotational axis may extend perpendicular to or at least substantially perpendicular to the blade rotation plane of the circular saw blade 170, and / or may extend parallel to or at least substantially parallel to the shaft rotation axis 154 of the motor 150. The attachment structure 50 may include any suitable structure adapted, configured, designed, and / or constructed to allow and / or facilitate limited rotational movement of the user actuation assembly 100 relative to the base structure 20 about the rotational axis 72. As an example, the attachment structure 50 may include a rotating element 70. Examples of rotating elements 70 include pivots and / or rotary bearings. The rotating element 70 may be configured to allow and / or facilitate... Figures 3 to 5 The non-pivot orientation 74 shown is... Figure 1 and Figure 2 The pivotal orientations 76 shown represent limited rotational motion along the axis of rotation 72.

[0037] In some examples, the attachment structure 50 may be configured to allow constrained relative movement between the base structure 20 and the user actuation component 100 along a linear axis of motion 62 (e.g., via...). Figure 1 and Figure 2 The transition between them is best shown) or the constrained relative motion about the rotational axis 72 (as may be achieved through) Figure 1 and Figure 3 The transition between them is best illustrated. Alternatively, in some examples, the attachment structure 50 may be configured to allow constrained relative movement between the base structure 20 and the user actuation component 100 along the linear axis of motion 62 and about the rotational axis of motion 72, as may be achieved through... Figure 1 and Figure 4 The transition between them is best illustrated. In some such examples, motion sensor 110 may be disposed on circuit board 180 within user actuation assembly 100. Additionally or alternatively, motion sensor 110 may be disposed on or along linear motion axis 62 and / or disposed on rotational motion axis 72. Motion sensor 110 may be disposed on user actuation assembly attachment portion 61 of linear guide 60 (e.g., shuttle) or rotating element 70, for example, to be subjected to only linear motion. In some such examples, battery pack may be attached to or can be attached to user actuation assembly 100 or user actuation assembly attachment portion of linear guide 60.

[0038] In some such examples, the motion sensor 110 can be mounted within the user actuation assembly 100, such that the motion sensor, together with the user actuation assembly 100, translates and rotates relative to the base structure 20. In some such examples, when or only when the user actuation assembly 100 is in pivot orientation 76, a linear detection axis 114, such as a first linear detection axis 116, can be aligned with a linear motion axis 62, as... Figure 1 and Figure 2 As shown.

[0039] In the example of a circular saw 10 in which the attachment structure 50 allows and / or facilitates limited rotational movement about the rotational motion axis 72, at least one linear detection axis 114 of the motion sensor 110 may be spaced apart from the rotational motion axis 72. This configuration allows and / or facilitates the measurement of rotational movement about the rotational motion axis 72 by the motion sensor 110. Additionally or alternatively, the motion sensor 110 may include a rotational detection axis 120, which may coincide with or at least substantially coincide with the rotational motion axis 72, for example... Figures 1 to 4 As shown. In some such examples, controller 190 may be programmed to initiate a recoil response if motion signal 112 indicates that the rotational speed about the rotational detection axis 120 is greater than a threshold rotational speed magnitude and / or when motion signal 112 indicates that the rotational speed about the rotational detection axis 120 is greater than the threshold rotational speed magnitude. The threshold rotational speed magnitude may be selected or predetermined based on one or more of a number of factors, such as the type of circular saw, the size of the circular saw blade, the expected rotational speed of the circular saw blade during the operation of the circular saw, manufacturing considerations, manufacturer and / or operator preferences, etc. As an example, a damper or fluid damper may be coupled to attachment structure 50 and user actuation assembly 100 to dampen movement in the direction of linear motion axis 62 and about rotational motion axis 72. Controller 190 may be configured to close the valve of the damper or fluid damper to increase resistance to movement of user actuation assembly 100 along linear motion axis 62 or dampen movement of user actuation assembly 100 along linear motion axis 62 as a recoil response. As another example, a rotary brake can be disposed on or between the attachment structure 50 and the user actuation component 100. The controller 190 can be configured to actuate or engage the rotary brake as a recoil response.

[0040] As discussed, controller 190 is also programmed to initiate a recoil response of the circular saw in response to a motion signal indicating a recoil condition. In some examples, controller 190 may be programmed to stop and / or dampen the movement of user actuation component 100 about the rotational axis of motion 72 as a recoil response, for example, by reducing the movement and / or acceleration of user actuation component 100 about the rotational axis of motion during a recoil state, or by reducing the likelihood of movement and / or acceleration of user actuation component 100 about the rotational axis of motion during a recoil state. In some such examples, circular saw 10 may include a rotational axis of motion braking structure 78, which may be configured to selectively resist or stop the movement of user actuation component 100 about the rotational axis of motion 72. In some such examples, controller 190 may be programmed to actuate rotational axis of motion braking structure 78 as a recoil response. Examples of rotational axis of motion braking structure 78 include any suitable damper, fluid damper, brake, brake pad, and / or friction enhancement device, which may be configured to stop and / or dampen the movement of user actuation component about the rotational axis of motion.

[0041] According to this disclosure, the circular saw 10 may include and / or may be any suitable type and / or category of circular saw, comprising a base structure 20, a user actuation assembly 100, an attachment structure 50, and a controller 190, and configured such that the workpiece support 40 of the base structure 20 faces the user actuation assembly 100. Examples of the circular saw 10 include fixed circular saws, semi-fixed circular saws, miter saws, compound miter saws, cleaving saws, sliding miter saws, compound sliding miter saws, panel saws, beveling saws, and / or swing arm saws. In all cases, the circular saw 10 according to this disclosure is configured such that the saw support 30 supports the circular saw and keeps the base structure 20 fixed, at least substantially fixed, stationary, or at least substantially stationary during operational use of the circular saw cutting a workpiece. However, and as discussed, the user actuation assembly 100 is configured to move relative to the base structure 20 and / or via the attachment structure 50 during operational use of the circular saw cutting a workpiece.

[0042] As used herein, the phrase "fixed circular saw" refers to a circular saw configured to be positioned and / or mounted in a fixed location during operational use, at least during the cutting of a workpiece. Such fixed circular saws are typically relatively heavy and not configured to be easily picked up and / or moved by the user, at least during operational use, at the time of cutting the workpiece.

[0043] As used herein, the phrase "semi-fixed circular saw" refers to a semi-portable circular saw that, while generally lighter than a corresponding type of fixed circular saw, is still configured to be positioned and / or selectively mounted in a fixed location during operational use of a fixed circular saw cutting a workpiece. Such a semi-fixed circular saw is typically configured to be easily picked up and / or moved by the user, but only before and / or after operational use of a fixed circular saw cutting a workpiece. In other words, the circular saw 10 according to this disclosure is not a handheld circular saw, i.e., a circular saw configured to be manually held, supported, and moved relative to a workpiece by a user during operational use of the saw.

[0044] Misizing saws, compound misizing saws, cleaving saws, sliding misizing saws, compound sliding misizing saws, panel saws, beveling saws, and radial saws all include a saw support configured to be fixed and operably support the circular saw during operation of cutting a workpiece. In other words, this circular saw is not configured to be easily picked up and / or moved by the user during operation of cutting a workpiece with a fixed circular saw. Misizing saws, compound misizing saws, beveling saws, and cleaving saws typically include a rotating element 70, but may not include a linear guide 60. Panel saws and radial saws typically include a linear guide 60, but may not include a rotating element 70. Sliding misizing saws and sliding compound misizing saws typically include both a linear guide 60 and a rotating element 70. Compound saws (e.g., compound misizing saws, compound sliding misizing saws) and / or beveling saws are typically configured to cut compound (i.e., multi-directional) angles within a workpiece.

[0045] The base structure 20 may include any suitable structure that may include and / or define the saw support 30 and the workpiece support 40. Examples of the base structure 20 include a metal base structure 20, a polymer base structure 20, an integral base structure 20, a single base structure 20, and / or an assembly of components defining the base structure 20.

[0046] The saw support 30 can be configured to support or operably support the circular saw 10 during operational use of the circular saw cutting a workpiece. This support can allow the base structure 20 to be stationary, or at least substantially stationary, during operational use of the circular saw cutting a workpiece.

[0047] In some examples, the saw support 30 includes and / or defines a saw support surface 32, which may be configured to rest against and / or be placed on another object, such as a table, stand, floor, and / or ground, during operational use of the circular saw cutting a workpiece. Alternatively, the saw support 30 may be configured to be directly and / or indirectly supported by the ground and / or configured to be unmovable, unsupported, and / or lifted by the user during operational use of the circular saw cutting a workpiece.

[0048] In some such examples, at least during the operation of the circular saw cutting a workpiece, the saw support surface 32 may include and / or may be horizontal or at least substantially horizontal. In some such examples, at least during the operation of the circular saw cutting a workpiece, the saw support surface 32 may face downwards, or at least substantially downwards. Examples of the saw support 30 include the support and / or lower surface of the base structure 20.

[0049] The workpiece support 40 can be configured to support or operably support the workpiece 90 during operational use of the circular saw cutting the workpiece. This can be accomplished in any suitable manner. As an example, the workpiece support 40 can have and / or define a workpiece support surface 42, which can be defined on the upper surface of the base structure 20. In some such examples, the workpiece 90 can be positioned on the workpiece support surface 42 during operational use of the circular saw cutting the workpiece. In some such examples, the workpiece support surface 42 can face the user actuation assembly 100 during operational use of the circular saw cutting the workpiece and / or be configured to support the workpiece between the workpiece support and the user actuation assembly.

[0050] In some such examples, the workpiece support surface 42 may include and / or may be horizontal or at least substantially horizontal. In some such examples, the workpiece support surface 42 may face upwards, or at least substantially upwards. In some such examples, the workpiece support surface 42 may be opposite to and / or parallel to or at least substantially parallel to the saw support surface 32.

[0051] The user actuation component 100 may include any suitable structure that can be operatively attached to the base structure 20 via the attachment structure 50. Additionally or alternatively, the user actuation component 100 may include any suitable structure that includes a motion sensor 110, a motor 150, a spindle 160, and / or can be configured to receive the circular saw blade 170 and / or provide rotational power for the circular saw blade to rotate in the plane of rotation of the blade.

[0052] Motion sensor 110 may include any suitable structure that can be adapted, configured, designed, and / or constructed to detect motion of user-actuated component 100 along and / or about a direction of motion and / or generate motion signal 112. As an example, motion sensor 110 may include and / or may be a microelectromechanical system (MEMS) motion sensor. Motion sensor 110 may be configured to detect acceleration along a single detection axis, along two perpendicular detection axes, and / or along three orthogonal detection axes. Additionally or alternatively, motion sensor 110 may be configured to detect rotation about a single detection axis, about two perpendicular detection axes, and / or about three orthogonal detection axes. In a specific example, motion sensor 110 may be configured to detect acceleration within an acceleration detection plane perpendicular to the axis of rotation 154 and / or parallel to the blade rotation plane. In another specific example, motion sensor 110 may be configured to detect rotation about a rotation detection axis that may be parallel to the axis of rotation 154. Such rotation may also be referred to herein as being detected within a rotation detection plane perpendicular to the axis of rotation 154 and / or parallel to the blade rotation plane.

[0053] Motor 150 may include any suitable structure that is adapted, configured, designed, and / or constructed to include a motor shaft 152 and / or to rotate the motor shaft about an axis of rotation 154. Examples of motor 150 include electric motors, AC electric motors, DC electric motors, brushless DC electric motors, variable speed motors, and / or single-speed motors.

[0054] The spindle 160 may include any suitable structure that is adapted, configured, designed, and / or constructed to operatively attach the circular saw blade 170 to the motor shaft 152 and / or to rotate the circular saw blade in the plane of blade rotation in response to rotation of the motor shaft. Examples of the spindle 160 include a spool, a flat-head spindle, a hexagonal-head spindle, a recessed hexagonal spindle, and / or a compression spindle.

[0055] The controller 190 may include any suitable structure, device, and / or multiple devices adapted, configured, designed, and / or programmed to receive motion signal 112, determine a recoil condition indicated by the motion signal, and / or initiate a recoil response of the circular saw in response to the motion signal indicating a recoil condition. As an example, the controller 190 may include one or more of an electronic controller, a dedicated controller, a special-purpose controller, a display device, a logic device, a storage device, and / or a storage device having a computer-readable storage medium.

[0056] Computer-readable storage media, as it exists, may also be referred to herein as non-transitory computer-readable storage media. Such non-transitory computer-readable storage media may include, define, contain, and / or store computer-executable instructions, programs, and / or code; and these computer-executable instructions may instruct the circular saw 10 and / or its controller 190 to perform any suitable portion or subset of method 200. Examples of such non-transitory computer-readable storage media include CD-ROMs, magnetic disks, hard disk drives, flash memory, etc. As used herein, storage devices or memories having computer-executable instructions according to this disclosure, devices and / or media, and computer-implemented methods and other methods are considered to be within the scope of patentable subject matter under Title 35, Section 101 of the United States Code.

[0057] In some examples, the user-actuated component 100 may include a circuit board 180, such as Figures 1 to 4 As shown. Circuit board 180, when present, may include and / or may define controller 190 and / or motion sensor 110. Additionally or alternatively, controller 190 may be otherwise incorporated into and / or operatively attached to user actuation component 100.

[0058] As discussed, controller 190 is programmed to initiate or selectively initiate a recoil response of the circular saw in response to motion signal 112 indicating a recoil condition. Within the scope of this disclosure, controller 190 can initiate any suitable recoil response. As an example, controller 190 can be programmed to interrupt the current supply to motor 150 and / or short-circuit or ground the stator coils of motor 150 as a recoil response.

[0059] As another example, controller 190 may be programmed to interrupt and / or stop the rotation of circular saw blade 170 and / or motor 150 as a recoil response. As a more specific example, circular saw 10 and / or its user-actuated assembly 100 may include brake assembly 80, which may be configured to selectively resist and / or stop the rotation of circular saw blade 170. In some such examples, controller 190 is programmed to actuate brake assembly 80 as a recoil response. Examples of brake assembly 80 include mechanical brake assemblies, brake pads, brake actuators, and / or brake cams, which may be configured to selectively engage with circular saw blade 170 and / or motor shaft and frictionally resist movement of circular saw blade 170 and / or motor shaft 152. Another example of brake assembly 80 includes an electric brake for motor 150, such as a reverse-field brake.

[0060] As another example, controller 190 may be programmed to interrupt the movement of user actuation component 100 along linear motion axis 62, for example, via actuation of linear motion axis braking structure 68. As yet another example, controller 190 may be programmed to interrupt the rotation of user actuation component 100 about rotational motion axis 72, for example, via actuation of rotational motion axis braking structure 78.

[0061] In some examples, controller 190 may be programmed to determine workpiece contact parameters that indicate contact or physical contact between the circular saw blade and the workpiece. In some such examples, the controller may also be programmed to initiate a recoil response of the circular saw when or only when the workpiece contact parameters indicate contact between the circular saw and the motion signal indicates a recoil condition. This configuration can reduce the likelihood of erroneous or undesirable initiation of a recoil response during periods when the motion signal may indicate a recoil condition but the circular saw is not being used to cut the workpiece. In other words, if the circular saw is struck, vibrated, or moved rapidly during periods when it is not actively used to cut the workpiece, an undesirable recoil response may be initiated, and the controller can utilize the workpiece contact parameters to prevent the initiation of such an undesirable recoil response. Examples of workpiece contact parameters are disclosed herein with reference to method 200.

[0062] The circular saw 10 may include other or additional components that may be included in a conventional circular saw. For example, and as... Figures 1 to 4 As shown by the dashed line, the circular saw 10 and / or its user-actuated component 100 may include a gripping area 130. The gripping area 130, when present, can be configured to be held and / or gripped by the user of the circular saw during operational use of the circular saw to cut a workpiece. For example, the user can cause the circular saw blade 170 to contact the workpiece 90 by means of, via, and / or by utilizing the gripping area 130.

[0063] As another example, and also as Figures 1 to 4 As shown by the dashed line, the circular saw 10 and / or its user actuation component 100 may include a switch 140. The switch 140, when present, can be configured to be selectively actuated by a user, for example, selectively applying current to at least one other part of the circular saw. In a specific example, actuation of the switch 140 may cause the circular saw 10 to rotate the circular saw blade 170 within the blade's plane of rotation.

[0064] As yet another example, and also as Figures 1 to 4 As shown by the dashed line, the circular saw 10 may include a power supply 185. The power supply 185, when present, may be adapted, configured, designed, and / or constructed to provide power or electricity to at least one other component of the circular saw 10 (e.g., motor 150 and / or controller 190). Examples of the power supply 185 include any suitable AC power source, DC power source, power cord, and / or battery.

[0065] Figure 9 This is a flowchart illustrating an example of a method 200 for detecting the recoil condition of a circular saw, including a circular saw blade, according to this disclosure. (See attached document for reference.) Figures 1 to 4 The circular saw 10 discloses an example of a circular saw. An example of a recoil condition is also disclosed in this document.

[0066] Method 200 includes rotating the circular saw blade at 210 and applying an actuating force at 220. Method 200 also includes moving the user actuation component at 230 and detecting the motion at 240. Method 200 may include detecting workpiece contact parameters at 250 and initiating a recoil response at 260.

[0067] Rotating the circular saw blade at 210 may include rotating the circular saw blade within its plane of rotation. This may include rotating the circular saw blade to allow and / or facilitate cutting of the workpiece, for example, during and / or in response to movement at 230. Examples of planes of rotation of the blade are disclosed herein.

[0068] Rotation at 210 can be accomplished in any suitable manner. As an example, rotation at 210 may include applying current to the motor of the circular saw. In response to this application, the motor may provide rotational power to the circular saw blade, which may produce and / or generate rotation at 210. As another example, rotation at 210 may include actuating a switch of the circular saw to apply current to the motor, wherein rotation at 210 is a response to actuation of the switch. An example of a motor is disclosed herein with reference to motor 150. An example of a switch is disclosed herein with reference to switch 140.

[0069] The rotation at 210 can be performed during method 200 at any suitable timing and / or sequence. As an example, the rotation at 210 can be performed before and / or at least partially concurrent with the application at 220, the movement at 230, the detection at 240, the detection at 250, and / or the initiation at 260.

[0070] Applying actuation force at 220 may include applying actuation force to the user-actuated components of the circular saw. This may include applying actuation force to allow, facilitate, and / or generate movement at 230. In some examples, application at 220 may be performed by the user of the circular saw. In other words, the actuation force may be applied by the user of the circular saw to, for example, the gripping area of ​​the circular saw. (See also: [link to document]) Figures 1 to 4 The user-actuated component 100 discloses an example of a user-actuated component. The gripping region 130 discloses an example of a gripping region.

[0071] The application at 220 can be performed during method 220 at any suitable timing and / or sequence. As an example, the application at 220 can be performed after and / or at least partially concurrent with the rotation at 210. As an additional example, the application at 220 can be performed before and / or at least partially concurrent with the movement at 230, the detection at 240, the detection at 250, and / or the start at 260. In a specific example, the application at 220 can be performed before the rotation at 210 begins. In some such examples, the subsequent rotation at 210 may produce and / or generate a recoil condition in the circular saw. Examples of recoil conditions are disclosed herein.

[0072] Moving the user-actuated component at 230 may include moving the user-actuated component relative to the base structure of the circular saw in the direction of motion. The movement at 230 may be performed during method 200 at any suitable timing and / or sequence. As an example, the movement at 230 may be performed after and / or at least partially simultaneously with the rotation at 210. As an additional example, the movement at 230 may be performed after, at least partially simultaneously with, and / or at least partially in response to the application at 220. As yet another example, the movement at 230 may be performed before and / or at least partially simultaneously with the detection at 240, the detection at 250, and / or the activation at 260. In a specific example, the movement at 230 may be performed before the rotation at 210 is initiated. In some such examples, the subsequent rotation at 210 may produce and / or generate a recoil condition in the circular saw.

[0073] In some examples, movement at 230 may include translating the user-actuated component along a linear motion axis or along a single linear motion axis. In some such examples, the linear motion axis may be parallel to or at least substantially parallel to the plane of blade rotation. Examples of linear motion axes are disclosed herein with reference to linear motion axis 62.

[0074] In some examples, movement at 230 may include rotating the user-actuated component about one or a single rotational motion axis. In some such examples, the rotational motion axis may extend perpendicular to or at least substantially perpendicular to the plane of blade rotation. An example of a rotational motion axis is disclosed herein with reference to rotational motion axis 72.

[0075] Detecting motion at 240 may include detecting motion of the user-actuated component along the direction of motion. Additionally or alternatively, detection at 240 may include detecting motion by means of, via, and / or using a motion sensor of the user-actuated component. Examples of motion sensors are disclosed herein with reference to motion sensor 110.

[0076] In an example where the movement at 230 includes a method 200 that translates a user-actuated component along a linear motion axis, the detection at 240 may include detecting the linear acceleration of the user-actuated component along the linear detection axis. As discussed in more detail herein, during the operational use of a circular saw cutting a workpiece, the linear motion axis may extend toward and / or away from the user. With this in mind, and in some examples, the detection at 230 may include detecting the linear acceleration of the user-actuated component toward the user of the circular saw. In an example where the movement at 230 includes a method 200 that rotates a user-actuated component about a rotational motion axis, the detection at 240 may include detecting the rotational speed of the user-actuated component about the rotational motion axis.

[0077] The detection at 240 can be performed during method 200 at any suitable timing and / or sequence. As an example, the detection at 240 can be performed before, after, and / or at least partially concurrent with the rotation at 210, the application at 220, the movement at 230, the detection at 250, and / or the initiation at 260.

[0078] Detecting workpiece contact parameters at 250 may include detecting any suitable workpiece contact parameters that can indicate contact between the circular saw blade and the workpiece. In other words, when the circular saw blade is in contact with the workpiece, the workpiece contact parameters can be within the contact value range. Conversely, when the circular saw blade is spaced apart from or not in contact with the workpiece, the workpiece contact parameters can be within the non-contact value range, which may differ from the contact value range. In such a configuration, activation at 260 may include initiating a recoil response when or only when the workpiece contact parameters are within the contact value range. In other words, when method 200 includes detection at 250, a workpiece contact parameter having a value within the contact value range may be a prerequisite that must be met before activation at 260.

[0079] In some examples, workpiece contact parameters may include and / or may be the angular velocity of the circular saw blade during rotation at 210°, the revolutions per minute (RPM) of the circular saw blade, the angular velocity of the motor shaft, and / or the RPM of the motor shaft. In this configuration, and when the circular saw blade is spaced from the workpiece and / or when the workpiece does not apply a load to the motor, the circular saw blade may define a mean free angular velocity, and the range of contact values ​​may include angular velocities below a threshold reduction in mean free angular velocity. Examples of threshold reductions in angular velocity include reductions of at least 20 revolutions per minute (RPM), at least 25 RPM, at least 30 RPM, at least 35 RPM, at least 40 RPM, at least 50 RPM, at least 60 RPM, at least 70 RPM, at least 80 RPM, at least 90 RPM, at least 100 RPM, at least 150 RPM, at least 200 RPM, at least 300 RPM, at least 400 RPM, at least 500 RPM, at least 600 RPM, at least 700 RPM, or at least 800 RPM.

[0080] In other words, the contact between the circular saw blade and the workpiece creates resistance to the rotation of the blade, thereby reducing its angular velocity to a value lower than its mean free angular velocity. Additionally, as discussed, recoil can occur due to the workpiece engaging and / or clamping the blade. This engagement and / or clamping also reduces the blade's angular velocity compared to its mean free angular velocity; and this reduction in angular velocity can be used to indicate that the blade is indeed in contact with the workpiece.

[0081] In such an example, the detection at 250 may include detecting the angular velocity of the circular saw blade and can be done in any suitable manner. As an example, detecting the angular velocity of the circular saw blade may include, for instance, measuring the angular velocity of the blade using a rotation counter of the circular saw. As another example, detecting the angular velocity of the circular saw blade may include calculating the angular velocity of the blade, for example, this may be based at least in part on a motor model of the circular saw's motor. In some such examples, calculating the angular velocity of the circular saw blade may include calculations based at least in part on the magnitude of the current supplied to the motor and / or the magnitude of the voltage of that current.

[0082] In some examples, workpiece contact parameters may include and / or may be the power consumption during the rotation of the circular saw blade at 210. In such a configuration, the motor may be limited to a maximum rated power consumption, and the range of contact values ​​may include power consumption greater than a threshold percentage of the maximum rated power consumption. Examples of threshold percentages of the maximum rated power consumption include, or at least, 50%, 60%, 70%, 80%, or 90%.

[0083] In other words, the contact between the circular saw blade and the workpiece creates resistance to the rotation of the blade, thus increasing the motor's power consumption. Additionally, as discussed, recoil can occur due to the workpiece engaging and / or clamping the blade. This engagement and / or clamping can also increase the motor's power consumption; and this increased power consumption can be used as an indication that the circular saw blade is indeed in contact with the workpiece.

[0084] In such an example, the detection at 250 may include detecting the power consumption of the motor and can be done in any suitable manner. As an example, detecting the power consumption of the motor may include calculating the motor's power consumption based at least in part on the magnitude of the current supplied to the motor and the magnitude of the voltage across that current.

[0085] In some examples, the circular saw may include a contact detector configured to detect contact between the circular saw blade and the workpiece. In some such examples, the contact detector may be configured to generate and / or generate workpiece contact parameters. Examples of contact detectors include electrical contact detectors, capacitive contact detectors, electromagnetic contact detectors, and / or mechanical contact detectors.

[0086] In some examples, workpiece contact parameters may include and / or may be based at least in part on the signal-to-noise ratio of the motion signal generated by detection at least in part at 240. As an example, the signal-to-noise ratio of the motion signal when the circular saw blade is in contact with the workpiece may be lower than when the blade is not in contact. This is in... Figures 6 to 8 As shown, the noise in the motion signal is relatively low before contact between the circular saw blade and the workpiece, as indicated by the time interval indicated by 99. Conversely, the noise in the motion signal is relatively high after contact between the circular saw blade and the workpiece, as indicated by the time interval indicated by 99.

[0087] In some examples, the workpiece contact parameters may be based at least in part on the magnitude of the acceleration of the user-actuated component measured during detection at 240. In some examples, the workpiece contact parameters may be based at least in part on the velocity of the user-actuated component in the direction of motion and / or in one direction or vector orientation of the direction of motion.

[0088] Initiating a recoil response at 260 may include initiating a recoil response of the circular saw in response to movement of a user-actuated component indicating a recoil condition of the circular saw. In some examples, initiation at 260 includes interrupting rotation at 210. In some such examples, the circular saw may include a brake assembly configured to be selectively actuated to stop rotation of the circular saw blade. In some such examples, initiation at 260 may include actuating the brake assembly to stop rotation of the circular saw blade. Examples of brake assemblies are disclosed herein with reference to brake assembly 80. In some examples, initiation at 260 may include interrupting the supply of current to the circular saw motor.

[0089] In examples where movement at 230 includes translating the user actuation component along a linear motion axis and / or where detection at 240 includes a method 200 for detecting linear acceleration of the user actuation component along a linear detection axis, activation at 260 may include initiating a recoil response when the linear acceleration is greater than a threshold linear acceleration magnitude. In some such examples, activation at 260 may include interrupting the movement of the user actuation component along the linear motion axis and / or damping the movement of the user actuation component along the linear motion axis, for example, using a linear motion axis braking structure utilizing a circular saw. An example of a linear motion axis braking structure is disclosed herein with reference to linear motion axis braking structure 68.

[0090] In some such examples, the linear detection axis may be a first linear detection axis, and the motion sensor may also include a second linear detection axis. The second linear detection axis may be perpendicular to the first linear detection axis, may be aligned with gravity, may be perpendicular to the horizontal direction, and / or may be parallel to the workpiece support. An example of a first linear detection axis 116 is disclosed herein. An example of a second linear detection axis 118 is disclosed herein. In such a configuration, activation at 260 may include initiating a recoil response when the vector sum of the linear accelerations along the first linear detection axis and the linear accelerations along the second linear acceleration axis is greater than a threshold linear acceleration magnitude. Additionally or alternatively, activation at 260 may include initiating a recoil response when the scalar sum of the absolute values ​​of the linear accelerations along the first linear detection axis and the absolute values ​​of the linear accelerations along the second linear detection axis is greater than a threshold linear acceleration magnitude. Examples of scalar sums of the absolute values ​​of linear accelerations that may initiate a recoil response include those greater than 5 m / s². 2 (greater than 8m / s) 2 greater than 10m / s 2 greater than 15m / s 2 and greater than 20m / s 2 The acceleration.

[0091] In an example where movement at 230 includes rotating the user-actuated component about a rotational motion axis and / or where detection at 240 includes a method 200 for detecting the rotational speed of the user-actuated component about a rotational detection axis, activation at 260 may include initiating a recoil response when the rotational speed is greater than a threshold rotational speed. Additionally or alternatively, activation at 260 may include interrupting the movement of the user-actuated component about the rotational motion axis and / or damping the movement of the user-actuated component about the rotational motion axis, for example, using a rotary motion braking structure utilizing a circular saw. An example of a rotary motion braking structure is disclosed herein with reference to rotary motion axis braking structure 78.

[0092] In this disclosure, several illustrative, non-exclusive examples have been discussed and / or presented in the context of flowcharts or schematic diagrams, wherein methods are shown and described as a series of boxes or steps. Unless specifically set forth in the accompanying description, within the scope of this disclosure, the order of boxes may differ from the order shown in the flowcharts, including two or more boxes (or steps) occurring in a different order and / or simultaneously. Also within the scope of this disclosure, one or more of these boxes or steps may be implemented as logic, which can also be described as implementing these boxes or steps as logic. In some applications, a box or step may represent a statement and / or action to be performed by a functionally equivalent circuit or other logic device. The boxes shown may, but are not required to, represent executable instructions that cause a computer, processor, and / or other logic device to respond, perform actions, change state, generate output or display, and / or make decisions.

[0093] As used herein, the word “and / or” between the first entity and the second entity refers to one of the following: (1) the first entity, (2) the second entity, and (3) the first entity and the second entity. Multiple entities listed with “and / or” should be interpreted in the same way, i.e., “one or more” of the entities so connected. In addition to the entities specifically identified by the “and / or” clause, there may optionally be other entities related to or unrelated to those specifically identified. Thus, as a non-limiting example, in one implementation, when used in conjunction with open-ended language such as “including,” a reference to “A and / or B” may refer only to A (optionally including entities other than B); in another implementation, only to B (optionally including entities other than A); and in yet another implementation, to both A and B (optionally including other entities). These entities may refer to elements, actions, structures, steps, operations, values, etc.

[0094] As used herein, the phrase "at least one" in relation to a list of one or more entities should be understood to mean at least one entity selected from any one or more entities in the list of entities, but not necessarily at least one of every entity specifically listed in the list of entities, and does not exclude any combination of entities in the list of entities. This limitation also allows for the optional presence of entities other than those specifically identified within the list of entities referred to by the phrase "at least one," which may be related to or unrelated to those specifically identified entities. 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") may in one embodiment mean at least one A, optionally including more than one A, without B (and optionally including entities other than B); in another embodiment, mean at least one B, optionally including more than one B, without A (and optionally including entities other than A); and in yet another embodiment, mean 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 conjunction and disjunctive in operation. For example, each of 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 refer to a single A, a single B, a single C, A and B together, A and C together, B and C together, A, B, and C together, and optionally any of the above combined with at least one other entity.

[0095] If any patent, patent application or other reference is incorporated herein by reference and (1) defines a term in a manner inconsistent with the non-incorporated portion of this disclosure or any other incorporated reference and / or (2) otherwise is inconsistent with the non-incorporated portion of this disclosure or any other incorporated reference, the non-incorporated portion of this disclosure shall be controlled, and the term or incorporated disclosure thereof shall be controlled only relative to the reference defining the term and / or the original reference in which the incorporated disclosure is located.

[0096] As used herein, the terms “suitable” and “configured” mean that an element, component, or other object is designed and / or intended to perform a given function. Therefore, the use of the terms “suitable” and “configured” should not be construed as meaning that a given element, component, or other object is simply “capable” of performing a given function, but rather that the element, component, and / or other object is specifically selected, created, implemented, utilized, programmed, and / or designed for the purpose of performing that function. Also within the scope of this disclosure, elements, components, and / or other listed objects enumerated as suitable for performing a particular function may additionally or alternatively be described as being configured to perform that function, and vice versa.

[0097] As used herein, the phrases “for example,” “as an example,” and / or simply the term “example,” when used with reference to one or more components, features, details, structures, embodiments, and / or methods according to this disclosure, are intended to convey illustrative, non-exclusive examples of the described components, features, details, structures, embodiments, and / or methods according to this disclosure. Therefore, the described components, features, details, structures, embodiments, and / or methods are not intended to be limiting, essential, or exclusive / exhaustive; and other components, features, details, structures, embodiments, and / or methods (including structurally and / or functionally similar and / or equivalent components, features, details, structures, embodiments, and / or methods) are also within the scope of this disclosure.

[0098] As used herein, when modifying degree or relation, "at least substantially" may include not only the listed "substantially" degree or relation, but also the entire range of the listed degree or relation. The substantially quantity of the listed degree or relation may include at least 75% of the listed degree or relation. For example, an object at least substantially formed of a certain material includes an object in which at least 75% of the object is formed of that material, and also includes an object formed entirely of that material. As another example, a first length at least substantially equal to a second length includes a first length within 75% of the second length, and also includes a first length equal to the second length.

[0099] Illustrative, non-exclusive examples of circular saws and methods according to this disclosure are presented in the following enumerated paragraphs. Within the scope of this disclosure, each step of the methods listed herein, including in the following enumerated paragraphs, may additionally or alternatively be referred to as a "step" for performing the enumerated actions.

[0100] A1. A circular saw having a blade that moves relative to a fixed base during operation of cutting a workpiece, the circular saw comprising:

[0101] The base structure includes saw supports and workpiece supports;

[0102] The user actuation component includes a motor, a spindle, and a motion sensor, wherein the motor includes a motor shaft configured to rotate about an axis of rotation, and further, its central shaft is operatively attached to the motor shaft and configured to receive a circular saw blade and rotate the circular saw in the plane of blade rotation.

[0103] An attachment structure, wherein the user actuation component is operably attached to a base structure such that the workpiece support faces the user actuation component, and further wherein the attachment structure is configured to allow constrained relative movement between the base structure and the user actuation component in the direction of motion and during operational use of the circular saw cutting the workpiece; and

[0104] A controller wherein a motion sensor is configured to detect the movement of a user-actuated component along a direction of motion and generate a motion signal indicative of the movement of the user-actuated component along the direction of motion, and further wherein the controller is programmed to receive the motion signal and, in response to the motion signal indicative of the recoil condition of the circular saw, initiate a recoil response of the circular saw.

[0105] A2. The circular saw according to paragraph A1, wherein the attachment structure is configured to allow constrained relative movement between the base structure and the user actuation component in response to receiving an actuation force from the user of the circular saw.

[0106] A3. Based on the circular saw in either paragraph A1 or A2, the direction of motion includes one or a single linear motion component.

[0107] A4. According to the circular saw in paragraph A3, the linear motion component is along one or a single linear motion axis.

[0108] A5. According to paragraph A4, the circular saw has a linear motion axis that is parallel to or at least substantially parallel to the plane of rotation of the blade.

[0109] A6. A circular saw according to either paragraph A4 or A5, wherein the attachment structure includes a linear guide configured to facilitate a limited linear movement of the user actuation component along a linear motion axis relative to the base structure.

[0110] A7. According to the circular saw in paragraph A6, the linear guide is configured to allow the user actuation component to move a limited linearly relative to the base structure between a retracted orientation and a protruding orientation.

[0111] A8. A circular saw based on any of paragraphs A4 to A7, wherein the motion sensor includes a linear detection axis that is aligned with or at least substantially aligned with the linear motion axis.

[0112] A9. According to the circular saw in paragraph A8, the controller is programmed to initiate a recoil response when the motion signal indicates that the linear acceleration along the linear detection axis is greater than a threshold linear acceleration magnitude.

[0113] A10. A circular saw according to any one of paragraphs A8 and A9, wherein the linear detection axis is a first linear detection axis, and further wherein the motion sensor includes a second linear detection axis, which is at least one of the following:

[0114] (i) Perpendicular to or at least substantially perpendicular to the first linear detection axis;

[0115] (ii) Consistent with or at least substantially consistent with gravity.

[0116] (iii) Perpendicular to or at least substantially perpendicular to the horizontal direction; and

[0117] (iv) Parallel to or at least substantially parallel to the workpiece.

[0118] A11. The circular saw according to paragraph A10, wherein the controller is programmed to initiate a recoil response when the motion signal indicates at least one of the following:

[0119] (i) The vector sum of the linear acceleration along the first linear detection axis and the linear acceleration along the second linear detection axis is greater than one / the threshold linear acceleration magnitude; and

[0120] (ii) The scalar sum of the absolute values ​​of the linear acceleration along the first linear detection axis and the absolute values ​​of the linear acceleration along the second linear detection axis is greater than one of the threshold linear acceleration magnitudes.

[0121] A12. A circular saw based on any one of paragraphs A4 to A11, wherein the controller is programmed to perform at least one of the following:

[0122] (i) stopping the motion of the user-actuated component along the linear motion axis as a recoil response; and

[0123] (ii) The motion of the damped user actuation component along the linear motion axis is used as a recoil response.

[0124] A13. A circular saw according to any of paragraphs A4 to A11, wherein the circular saw includes a linear motion axis braking structure configured to selectively resist movement of a user-actuated component along a linear motion axis, and further wherein a controller is programmed to actuate the linear motion axis braking structure as a recoil response.

[0125] A14. A circular saw based on any one of paragraphs A1 to A13, wherein the direction of motion includes one or a single rotational motion component.

[0126] A15. According to the circular saw in paragraph A14, the rotational motion component is about the rotational motion axis.

[0127] A16. A circular saw according to paragraph A15, wherein the axis of rotational motion is perpendicular or at least substantially perpendicular to the plane of rotation of the blade.

[0128] A17. A circular saw according to either paragraph A15 or A16, wherein the attachment structure includes a rotating element configured to facilitate a limited rotational movement of the user actuation assembly relative to the base structure about a rotational motion axis.

[0129] A18. The circular saw according to paragraph A17, wherein the rotating element is configured to allow the user actuating assembly to perform limited rotational movement relative to the base structure between a non-pivoting orientation and a pivoting orientation.

[0130] A19. According to the circular saw in paragraph A18, when belonging to any of paragraphs A8 to A11, where the linear detection axis is aligned with the linear motion axis when the user actuation component is in pivot orientation.

[0131] A20. Based on any of paragraphs A15 to A19, a circular saw, wherein the linear detection axis of the motion sensor is spaced apart from the rotational motion axis.

[0132] A21. A circular saw according to any of paragraphs A15 to A20, wherein the motion sensor includes a rotational detection axis that is aligned with or at least substantially aligned with the axis of rotational motion.

[0133] A22. According to the circular saw in paragraph A21, the controller is programmed to initiate a recoil response when the motion signal indicates that the speed around the rotational detection axis is greater than a threshold rotational speed.

[0134] A23. A circular saw based on any one of paragraphs A15 to A22, wherein the controller is programmed to perform at least one of the following:

[0135] (i) stopping the motion of the user-actuated component about the rotational axis of motion as a recoil response; and

[0136] (ii) The motion of the damped user-actuated component around the rotational axis of motion is used as a recoil response.

[0137] A24. A circular saw according to any of paragraphs A15 to A23, wherein the circular saw includes a rotary axis braking structure configured to selectively resist movement of a user-actuated component about a rotary axis, and further wherein a controller is programmed to actuate the rotary axis braking structure as a recoil response.

[0138] A25. A circular saw according to any one of paragraphs A1 to A24, wherein the circular saw includes at least one of a fixed circular saw, a semi-fixed circular saw, a miter saw, a compound miter saw, a splitting saw, a sliding miter saw, a compound sliding miter saw, a panel saw, a beveling saw, and a rocker arm saw.

[0139] A26. A circular saw based on any of paragraphs A1 to A25, wherein the circular saw is not a handheld circular saw.

[0140] A27. A circular saw according to any of paragraphs A1 to A26, wherein the saw support is configured to support the circular saw during its operational use in cutting a workpiece.

[0141] A28. A circular saw according to any of paragraphs A1 to A27, wherein the saw support defines the saw support surface.

[0142] A29. A circular saw according to paragraph A28, wherein the saw support surface is horizontal or at least substantially horizontal.

[0143] A30. A circular saw according to either paragraph A28 or A29, wherein the saw support surface is facing down, or at least substantially facing down.

[0144] A31. A circular saw based on any one of paragraphs A1 to A30, including at least one of the following:

[0145] (i) The saw support is configured to be directly supported by the ground during the operation of the circular saw cutting the workpiece;

[0146] (ii) The saw support is configured to be indirectly supported by the ground during the operational use of the circular saw for cutting workpieces; and

[0147] (iii) The saw support is not configured to be moved by the user during operation of the circular saw cutting the workpiece.

[0148] A32. A circular saw according to any of paragraphs A1 to A31, wherein a workpiece support defines a workpiece support surface configured to support the workpiece during the operation of the circular saw cutting the workpiece.

[0149] A33. According to the circular saw in paragraph A32, the workpiece support surface is horizontal or at least substantially horizontal.

[0150] A34. A circular saw according to either paragraph A32 or A33, wherein the workpiece support surface faces upward, or at least substantially upward.

[0151] A35. A circular saw according to any one of paragraphs A32 to A34, wherein the workpiece support surface is at least one of the following:

[0152] (i) Opposite to the saw support surface;

[0153] (ii) Parallel to the saw support surface; and

[0154] (iii) At least substantially parallel to the saw support surface.

[0155] A36. A circular saw based on any of paragraphs A1 to A35, wherein the motion sensor includes or is a microelectromechanical system (MEMS) motion sensor.

[0156] A37. A circular saw based on any one of paragraphs A1 to A36, wherein the motion sensor is configured to perform at least one of the following:

[0157] (i) Detect acceleration along a single detection axis;

[0158] (ii) Detect acceleration along two perpendicular detection axes;

[0159] (iii) Detect acceleration along three orthogonal detection axes;

[0160] (iv) Detect rotation about a single detection axis;

[0161] (v) Detecting rotation about two perpendicular detection axes; and

[0162] (vi) Detect rotation around three orthogonal detection axes.

[0163] A38. A circular saw according to any one of paragraphs A1 to A37, wherein a motion sensor is configured to detect acceleration in an acceleration detection plane, the acceleration detection plane being at least one of the following:

[0164] (i) Perpendicular to the axis of rotation; and

[0165] (ii) Parallel to the plane of blade rotation.

[0166] A39. A circular saw according to any one of paragraphs A1 to A38, wherein a motion sensor is configured to detect rotation within a rotation detection plane, the rotation detection plane being at least one of the following:

[0167] (i) Perpendicular to the axis of rotation;

[0168] (ii) Parallel to the plane of blade rotation; and

[0169] (iii) Parallel to one of the acceleration detection planes.

[0170] A40. A circular saw according to any of paragraphs A1 to A39, wherein the user-actuated component includes a circuit board that includes both a controller and a motion sensor.

[0171] A41. A circular saw based on any one of paragraphs A1 to A40, wherein the user-actuated component includes a controller.

[0172] A42. A circular saw based on any of paragraphs A1 to A41, wherein the controller is also programmed to perform any appropriate step of any method in any of paragraphs B1 to B28.

[0173] A43. A circular saw based on any of paragraphs A1 to A42, wherein the controller is programmed to stop the rotation of the circular saw blade as a recoil response.

[0174] A44. A circular saw according to paragraph A43, wherein the circular saw further includes a brake assembly configured to be selectively actuated to stop the rotation of the circular saw blade, and further wherein the controller is programmed to actuate the brake assembly as a recoil response.

[0175] A45. Based on the circular saw in either paragraph A43 or A44, where the controller is programmed to interrupt the current supply to the motor as a recoil response.

[0176] A46. A circular saw according to any of paragraphs A43 to A45, wherein the controller is further programmed to determine workpiece contact parameters, wherein the workpiece contact parameters are within the contact value range when the circular saw blade is in contact with the workpiece, wherein the workpiece contact parameters are within the non-contact value range when the circular saw blade is spaced apart from the workpiece, and further wherein the controller is programmed to determine that a backlash condition exists when or only when the workpiece contact parameters are within the contact value range.

[0177] A47. A circular saw according to paragraph A46, wherein the workpiece contact parameter includes the angular velocity of at least one of the motor and the circular saw blade during the operation of the circular saw cutting the workpiece, wherein the angular velocity defines the mean free angular velocity when the circular saw blade is spaced apart from the workpiece, and further wherein the contact value range includes angular velocities below a threshold angular velocity reduction, optionally wherein the threshold angular velocity reduction is at least 20 revolutions per minute (RPM), at least 25 RPM, at least 30 RPM, at least 35 RPM, at least 40 RPM, at least 50 RPM, at least 60 RPM, at least 70 RPM, at least 80 RPM, at least 90 RPM, at least 100 RPM, at least 150 RPM, at least 200 RPM, at least 300 RPM, at least 400 RPM, at least 500 RPM, at least 600 RPM, at least 700 RPM, or at least 800 RPM.

[0178] A48. A circular saw based on paragraph A47, where the controller is programmed to measure the angular velocity of the circular saw blade.

[0179] A49. A circular saw based on either paragraph A47 or A48, wherein the controller is programmed to calculate the angular velocity of the circular saw blade based at least in part on a motor model of the motor.

[0180] A50. A circular saw according to any of paragraphs A47 to A49, wherein the controller is programmed to calculate the angular velocity of the circular saw blade based at least in part on the magnitude of the current supplied to the motor and the magnitude of the voltage of the current.

[0181] A51. A circular saw according to any of paragraphs A46 to A50, wherein the workpiece contact parameter includes at least one of the current consumption and power consumption of the circular saw blade during the operation of the circular saw cutting the workpiece, wherein the motor of the circular saw limits a maximum rated consumption, and further wherein the contact value range includes consumption greater than a threshold percentage of the maximum rated consumption, optionally wherein the threshold percentage of the maximum rated consumption is 50%, 60%, 70%, 80%, or 90%.

[0182] A52. A circular saw according to any of paragraphs A46 to A51, wherein the circular saw includes a contact detector configured to detect contact between the circular saw blade and the workpiece, and further wherein the contact detector is configured to generate workpiece contact parameters.

[0183] A53. The circular saw according to paragraph A52, wherein the contact detector comprises at least one of the following contactors:

[0184] (i) Electrical contact detector;

[0185] (ii) Capacitive contact detector;

[0186] (iii) Electromagnetic contact detector; and

[0187] (iv) Mechanical contact detector.

[0188] A54. A circular saw based on any of paragraphs A46 to A53, wherein the workpiece contact parameters are based at least in part on the signal-to-noise ratio of the motion signal.

[0189] A55. A circular saw according to any of paragraphs A46 to A54, wherein the workpiece contact parameters are based at least in part on the magnitude of the acceleration of the user-actuated component measured during the operation of the circular saw cutting the workpiece.

[0190] A56. A circular saw according to any of paragraphs A46 to A55, wherein the workpiece contact parameters are based at least in part on at least one of the following:

[0191] (i) the velocity of the user-actuated component in the direction of motion; and

[0192] (ii) The direction of the motion.

[0193] A57. A circular saw according to any of paragraphs A1 to A56, wherein the user-actuated component further includes a gripping area configured to be gripped by the user of the circular saw to cause the circular saw blade to contact the workpiece during operation of the circular saw cutting the workpiece.

[0194] A58. A circular saw according to any of paragraphs A1 to A57, wherein the user-actuated component further includes a switch configured to be selectively actuated by a user to selectively apply current to at least one other part of the circular saw.

[0195] A59. A circular saw according to any of paragraphs A1 to A58, wherein the user-actuated component further includes a circular saw blade, wherein the circular saw blade is operatively attached to a motor via a spindle.

[0196] B1. A method for detecting the recoil condition of a circular saw including a circular saw blade, the method comprising:

[0197] To make the circular saw blade rotate within the plane of blade rotation;

[0198] Apply actuating force to the user-actuated components of the circular saw;

[0199] In response to this application, the user-actuated component moves relative to the base structure of the circular saw in the direction of motion;

[0200] The motion sensor of the user actuation component is used to detect the motion of the user actuation component along the direction of motion; and

[0201] The circular saw's recoil response is initiated in response to the movement of the user-actuated component that indicates the recoil status of the circular saw.

[0202] B2. According to the method in paragraph B1, the detection further includes detecting workpiece contact parameters, wherein when the circular saw blade is in contact with the workpiece, the workpiece contact parameters are within the contact value range, wherein when the circular saw blade is spaced apart from the workpiece, the workpiece contact parameters are within the non-contact value range, and further, wherein the method includes determining that a backlash condition exists when or only when the workpiece contact parameters are within the contact value range.

[0203] B3. According to the method in paragraph B2, wherein the workpiece contact parameters include the angular velocity of at least one of the motor and the circular saw blade during rotation, wherein the angular velocity defines the mean free angular velocity when the circular saw blade is spaced apart from the workpiece, and further wherein the contact value range includes angular velocities below a threshold angular velocity reduction, optionally wherein the threshold angular velocity reduction is at least 20 revolutions per minute (RPM), at least 25 RPM, at least 30 RPM, at least 35 RPM, at least 40 RPM, at least 50 RPM, at least 60 RPM, at least 70 RPM, at least 80 RPM, at least 90 RPM, at least 100 RPM, at least 150 RPM, at least 200 RPM, at least 300 RPM, at least 400 RPM, at least 500 RPM, at least 600 RPM, at least 700 RPM, or at least 800 RPM.

[0204] B4. According to the method in paragraph B3, detecting workpiece contact parameters includes measuring the angular velocity of the circular saw blade.

[0205] B5. The method according to either paragraph B3 or B4, wherein detecting workpiece contact parameters includes calculating the angular velocity of the circular saw blade based at least in part on a motor model of the circular saw's motor.

[0206] B6. According to the method in paragraph B5, the calculation of the angular velocity of the circular saw blade also includes calculating the angular velocity of the circular saw blade based at least in part on the magnitude of the current supplied to the motor and the magnitude of the voltage of the current.

[0207] B7. The method according to any one of paragraphs B2 to B6, wherein the workpiece contact parameters include at least one of the current consumption and power consumption of the circular saw blade during rotation, wherein the motor of the circular saw defines a maximum rated consumption, and further wherein the contact value range includes consumption greater than a threshold percentage of the maximum rated consumption, optionally wherein the threshold percentage of the maximum rated consumption is 50%, 60%, 70%, 80%, or 90%.

[0208] B8. The method according to any one of paragraphs B2 to B7, wherein the circular saw includes a contact detector configured to detect contact between the circular saw blade and the workpiece, and further wherein the contact detector is configured to generate workpiece contact parameters.

[0209] B9. The method according to paragraph B8, wherein the contact detector comprises at least one of the following contactors:

[0210] (i) Electrical contact detector;

[0211] (ii) Capacitive contact detector;

[0212] (iii) Electromagnetic contact detector; and

[0213] (iv) Mechanical contact detector.

[0214] B10. The method according to any one of paragraphs B2 to B9, wherein the workpiece contact parameters are based at least in part on the detected signal-to-noise ratio.

[0215] B11. The method according to any one of paragraphs B2 to B10, wherein the workpiece contact parameters are based at least in part on the magnitude of the acceleration of the user-actuated component measured during the inspection.

[0216] B12. The method according to any one of paragraphs B2 to B11, wherein the workpiece contact parameters are based at least in part on at least one of the following:

[0217] (i) the velocity of the user-actuated component in the direction of motion; and

[0218] (ii) The direction of the motion.

[0219] B13. The method described in any of paragraphs B1 to B12, wherein the application of actuation force is performed by the user of the circular saw.

[0220] B14. The method according to any of paragraphs B1 to B13, wherein moving the user actuation component includes translating the user actuation component along one or a single linear motion axis.

[0221] B15. According to the method in paragraph B14, the linear motion axis is parallel to or at least substantially parallel to the plane of blade rotation.

[0222] B16. The method according to either paragraph B14 or B15, wherein detecting motion includes detecting linear acceleration of the user along a linear detection axis and optionally toward the circular saw.

[0223] B17. According to the method in paragraph B16, the initiation of the recoil response includes initiating the recoil response when the linear acceleration is greater than a threshold linear acceleration magnitude.

[0224] B18. The method according to any one of paragraphs B16 and B17, wherein the linear detection axis is a first linear detection axis, wherein the motion sensor includes a second linear detection axis, the second linear detection axis being at least one of being perpendicular to the first linear detection axis, aligned with gravity, perpendicular to the horizontal direction, and parallel to the workpiece support of the circular saw, and further wherein initiating the recoil response includes initiating the recoil response when at least one of the following conditions occurs:

[0225] (i) The vector sum of the linear accelerations along the first linear detection axis and the linear accelerations along the second linear detection axis is greater than the threshold linear acceleration magnitude; and

[0226] (ii) The scalar sum of the absolute values ​​of linear acceleration along the first linear detection axis and the absolute values ​​of linear acceleration along the second linear detection axis is greater than the threshold linear acceleration magnitude.

[0227] B19. According to the method of any one of paragraphs B14 to B18, the initiation of the recoil response includes at least one of the following:

[0228] (i) interrupting the motion of the user-actuated component along the linear motion axis; and

[0229] (ii) The movement of the damped user actuation component along the linear motion axis.

[0230] B20. The method according to any one of paragraphs B1 to B19, wherein moving the user actuation component includes rotating the user actuation component about one or a single rotational motion axis.

[0231] B21. According to the method in paragraph B20, the axis of rotational motion is perpendicular to or at least substantially perpendicular to the plane of blade rotation.

[0232] B22. The method according to either paragraph B20 or B21, wherein detecting motion includes detecting rotational speed about the axis of rotational motion.

[0233] B23. According to the method in paragraph B22, the initiation of the recoil response includes initiating the recoil response when the rotational speed is greater than a threshold rotational speed.

[0234] B24. According to the method in either paragraph B22 or B23, the initiation of the recoil response includes at least one of the following:

[0235] (i) interrupting the motion of the user-actuated component about the rotational axis; and

[0236] (ii) The motion of the damped user actuation component around the axis of rotation.

[0237] B25. According to the method in any of paragraphs B1 to B24, the initiation of the recoil response includes interrupting the rotation.

[0238] B26. The method according to any one of paragraphs B1 to B25, wherein the circular saw includes a brake assembly configured to be selectively actuated to stop the rotation of the circular saw blade, and further wherein initiating a recoil response includes actuating the brake assembly to stop the rotation of the circular saw blade.

[0239] B27. The method described in any of paragraphs B1 to B26, wherein initiating the recoil response includes interrupting the current supply to the motor of the circular saw.

[0240] B28. The method according to any of paragraphs B1 to B27, wherein the circular saw includes any suitable structure of any circular saw in any of paragraphs A1 to A59.

[0241] B29. A non-transient computer-readable storage medium comprising computer-executable instructions that, when executed, instruct a controller of a circular saw to perform any suitable step of any method of any of paragraphs B1 to B28.

[0242] Industrial applicability

[0243] The circular saw and methods disclosed in this article are applicable to the power tool industry.

[0244] It is believed that the above disclosure covers several different inventions with independent utility. While each of these inventions is disclosed in its preferred form, the specific embodiments of these inventions disclosed and illustrated herein should not be considered limiting, as many variations are possible. The subject matter of this 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 enumerates a "one" or "first" element or its equivalent, such a claim should be understood to include the incorporation of one or more such elements, neither requiring nor excluding two or more such elements.

[0245] It is believed that the appended claims specifically point to certain combinations and sub-combinations of features, functions, elements, and / or characteristics that are novel and non-obvious, relating to one of the disclosed inventions. Other combinations and sub-combinations of features, functions, elements, and / or characteristics may be claimed by amending the current claims or by setting new claims in this or related applications. These amended or new claims, whether they pertain to different or the same invention, and whether their scope differs from, is broader, narrower, or identical to that of the original claims, are also considered to be included within the subject matter of the invention disclosed herein.

Claims

1. A circular saw having a blade that moves relative to a fixed base during operation of cutting a workpiece, the circular saw comprising: The base structure includes saw supports and workpiece supports; The user-actuated component includes a motor, a spindle, and a motion sensor, wherein the motor includes a motor shaft configured to rotate about an axis of rotation, wherein the spindle is operatively attached to the motor shaft and configured to receive a circular saw blade and rotate the circular saw in a plane of blade rotation. An attachment structure, wherein the user actuation component is operably attached to the base structure via the attachment structure such that the workpiece support faces the user actuation component, wherein the attachment structure is configured to allow constrained relative movement between the base structure and the user actuation component in the direction of motion and during the operation of the circular saw cutting the workpiece. as well as A controller, wherein the motion sensor is configured to detect the motion of the user actuation component along the direction of motion and generate a motion signal indicating the motion of the user actuation component along the direction of motion, wherein the controller is programmed to receive the motion signal and initiate a recoil response of the circular saw in response to the motion signal indicating the recoil condition of the circular saw. The motion direction includes a single linear motion component along a linear motion axis, wherein the attachment structure includes a linear guide configured to facilitate a limited linear motion of the user actuation component relative to the base structure along the linear motion axis, and the motion direction includes a single rotational motion component about a rotational motion axis, wherein the attachment structure includes a rotating element configured to facilitate a limited rotational motion of the user actuation component about the rotational motion axis relative to the base structure; and The motion sensor includes a linear detection axis spaced apart from the rotational motion axis.

2. The circular saw according to claim 1, wherein the motion sensor includes a linear detection axis that is at least substantially aligned with the linear motion axis.

3. The circular saw of claim 2, wherein the controller is programmed to initiate the recoil response when the motion signal indicates that the linear acceleration along the linear detection axis is greater than a threshold linear acceleration.

4. The circular saw according to claim 2 or 3, wherein the linear detection axis is a first linear detection axis, and wherein the motion sensor includes a second linear detection axis, the second linear detection axis being at least one of the following: (i) At least substantially perpendicular to the first linear detection axis; (ii) is at least substantially consistent with gravity; (iii) At least substantially perpendicular to the horizontal direction; and (iv) At least substantially parallel to the workpiece support.

5. The circular saw of claim 4, wherein the controller is programmed to initiate the recoil response when the motion signal indicates at least one of the following: (i) The vector sum of the linear acceleration along the first linear detection axis and the linear acceleration along the second linear detection axis is greater than the threshold linear acceleration magnitude; and (ii) The scalar sum of the absolute values ​​of the linear acceleration along the first linear detection axis and the absolute values ​​of the linear acceleration along the second linear detection axis is greater than the threshold linear acceleration magnitude.

6. The circular saw according to any one of claims 1 to 3, wherein the circular saw includes a linear motion axis braking structure configured to selectively resist movement of the user actuation component along the linear motion axis, wherein the controller is programmed to actuate the linear motion axis braking structure as the recoil response.

7. The circular saw of claim 1, wherein the motion sensor includes a rotation detection axis that is at least substantially aligned with the rotational motion axis.

8. The circular saw of claim 7, wherein the controller is programmed to initiate the recoil response when the motion signal indicates that the speed around the rotation detection axis is greater than a threshold rotation speed.

9. The circular saw according to any one of claims 1 to 3, comprising at least one of the following: (i) The motion sensor is mounted on the linear motion axis; (ii) The motion sensor is disposed on the axis of rotation; (iii) The motion sensor is disposed on the user actuation component attachment portion of the linear guide such that the motion sensor is subjected to only linear motion; as well as (iv) The motion sensor is mounted on the rotating element such that the motion sensor is subjected to only linear motion.

10. The circular saw of claim 9, wherein the battery pack is attached to at least one of the following components: (i) the user actuation component; and (ii) The user actuation component attachment portion of the linear guide.

11. The circular saw according to any one of claims 1 to 3, wherein the circular saw includes a rotary axis braking structure configured to selectively resist movement of the user actuation component about the rotary axis, wherein the controller is programmed to actuate the rotary axis braking structure as the recoil response.

12. The circular saw according to any one of claims 1 to 3, wherein the controller is programmed to stop the rotation of the circular saw blade as the recoil response.

13. The circular saw according to any one of claims 1 to 3, wherein the circular saw further comprises a brake assembly configured to be selectively actuated to stop rotation of the circular saw blade, wherein the controller is programmed to actuate the brake assembly as the recoil response.

14. The circular saw according to any one of claims 1 to 3, wherein the controller is programmed to perform at least one of the following: (i) Interrupting the current supply to the motor as the recoil response; (ii) Short-circuiting the stator coils of the motor as the recoil response; and (iii) The stator coil of the motor is short-circuited to ground as the recoil response.

15. The circular saw according to any one of claims 1 to 3, wherein the controller is further programmed to determine workpiece contact parameters, wherein, When the circular saw blade contacts the workpiece, the workpiece contact parameter is within the contact value range, wherein when the circular saw blade is spaced apart from the workpiece, the workpiece contact parameter is within the non-contact value range, wherein the controller is programmed to determine that the recoil condition exists only when the workpiece contact parameter is within the contact value range.

16. The circular saw of claim 15, wherein the workpiece contact parameter includes the angular velocity of at least one of the motor and the circular saw blade during operation of the circular saw cutting the workpiece, wherein, When the circular saw blade is spaced apart from the workpiece, the angular velocity defines the mean free angular velocity, wherein the contact value range includes angular velocities at least 20 revolutions per minute lower than the mean free angular velocity.

17. The circular saw of claim 15, wherein the workpiece contact parameter includes at least one of the current consumption and power consumption of the circular saw blade during operation of the circular saw cutting the workpiece, wherein the motor of the circular saw is limited to a maximum rated consumption, and wherein the contact value range includes consumption greater than 50% of the maximum rated consumption.

18. The circular saw of claim 15, wherein the circular saw includes a contact detector configured to detect contact between the circular saw blade and the workpiece, wherein the contact detector is configured to generate workpiece contact parameters.

19. The circular saw of claim 15, wherein the workpiece contact parameters are at least partially based on the signal-to-noise ratio of the motion signal.

20. The circular saw of claim 15, wherein the workpiece contact parameters are based at least in part on the magnitude of the acceleration of the user-actuated component measured during operation of the circular saw cutting the workpiece.

21. The circular saw of claim 15, wherein the workpiece contact parameters are based, at least in part, on at least one of the following: (i) the velocity of the user actuation component in the direction of motion; and (ii) The direction of the motion.

22. The circular saw according to any one of claims 1 to 3, wherein the circular saw comprises at least one of a fixed circular saw, a semi-fixed circular saw, a miter saw, a compound miter saw, a splitting saw, a sliding miter saw, a compound sliding miter saw, a panel saw, a beveling saw, and a rocker arm saw.

23. A method for detecting the recoil condition of a circular saw, the circular saw comprising a circular saw blade, the method comprising: The circular saw blade rotates within the blade's plane of rotation. as well as Apply actuation force to the user actuation component of the circular saw; In response to the application, the user actuation component is moved in the direction of motion relative to the base structure of the circular saw; The motion sensor of the user actuation component is used to detect the motion of the user actuation component along the direction of motion; as well as In response to the movement of the user-actuated component indicating the recoil condition of the circular saw, the recoil response of the circular saw is initiated; Wherein, the direction of motion includes a single linear motion component along a linear motion axis, and The direction of motion includes a single rotational motion component around the rotational axis, and The motion sensor includes a linear detection axis spaced apart from the rotational motion axis.

24. The method of claim 23, wherein the detection further includes detecting workpiece contact parameters, wherein, When the circular saw blade contacts the workpiece, the workpiece contact parameter is within the contact value range, wherein when the circular saw blade is spaced apart from the workpiece, the workpiece contact parameter is within the non-contact value range, wherein the method includes determining that the recoil condition exists when or only when the workpiece contact parameter is within the contact value range.

25. The method of claim 24, wherein the workpiece contact parameters include the angular velocity of at least one of the motor and the circular saw blade during rotation, wherein, When the circular saw blade is spaced apart from the workpiece, the angular velocity defines the mean free angular velocity, wherein the contact value range includes angular velocities at least 20 revolutions per minute lower than the mean free angular velocity.

26. The method of claim 24 or 25, wherein the workpiece contact parameter includes at least one of the current consumption and power consumption of the circular saw blade during rotation, wherein the motor of the circular saw defines a maximum rated consumption, and wherein the contact value range includes consumption greater than 50% of the maximum rated consumption.

27. The method of claim 24 or 25, wherein the circular saw includes a contact detector configured to detect contact between the circular saw blade and the workpiece, wherein the contact detector is configured to generate workpiece contact parameters.

28. The method of claim 24 or 25, wherein the workpiece contact parameters are at least partially based on the signal-to-noise ratio of the detection.

29. The method of claim 24 or 25, wherein the workpiece contact parameters are based at least in part on the magnitude of the acceleration of the user-actuated component measured during the detection.

30. The method of claim 24 or 25, wherein the workpiece contact parameters are based, at least in part, on at least one of the following: (i) the velocity of the user actuation component in the direction of motion; and (ii) The direction of the motion.

31. The method according to any one of claims 23 to 25, wherein moving the user actuation component comprises translating the user actuation component along a linear motion axis.

32. The method according to any one of claims 23 to 25, wherein detecting motion comprises detecting linear acceleration along a linear detection axis.

33. The method of claim 32, wherein initiating the recoil response comprises initiating the recoil response when the linear acceleration is greater than a threshold linear acceleration magnitude.

34. The method of claim 32, wherein the linear detection axis is a first linear detection axis, wherein the motion sensor includes a second linear detection axis, the second linear detection axis being at least one of being perpendicular to the first linear detection axis, aligned with gravity, perpendicular to the horizontal direction, and parallel to the workpiece support of the circular saw, wherein activating the recoil response includes activating the recoil response when at least one of the following occurs: (i) The vector sum of the linear acceleration along the first linear detection axis and the linear acceleration along the second linear detection axis is greater than the threshold linear acceleration magnitude; and (ii) The scalar sum of the absolute value of the linear acceleration along the first linear detection axis and the absolute value of the linear acceleration along the second linear detection axis is greater than the threshold linear acceleration magnitude.

35. The method of claim 31, wherein initiating the recoil response comprises at least one of the following: (i) Interrupt the movement of the user actuation component along the linear motion axis; and (ii) Damping the movement of the user-actuated component along the linear motion axis.

36. The method according to any one of claims 23 to 25, wherein moving the user actuation component comprises rotating the user actuation component about a rotational motion axis.

37. The method of claim 36, wherein detecting motion includes detecting rotational speed about the axis of rotational motion.

38. The method of claim 37, wherein initiating the recoil response comprises initiating the recoil response when the rotational speed is greater than a threshold rotational speed.

39. The method of claim 36, wherein initiating the recoil response comprises at least one of the following: (i) Interrupt the motion of the user actuation component about the rotational axis; and (ii) Damping the motion of the user-actuated component about the axis of rotational motion.

40. The method of any one of claims 23 to 25, wherein the circular saw includes a brake assembly configured to be selectively actuated to stop rotation of the circular saw blade, wherein initiating the recoil response includes actuating the brake assembly to stop rotation of the circular saw blade.

41. The method according to any one of claims 23 to 25, wherein initiating the recoil response comprises stopping the supply of current to the motor of the circular saw.

42. The method of claim 23, wherein the motion sensor includes a rotational detection axis that is at least substantially aligned with the rotational motion axis.

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