Chain saw and momentary switch for chain saw

Abstract

A chainsaw and a momentary switch for a chainsaw are disclosed. A chainsaw includes: a guide bar; the chain is arranged around the guide rod and can move relative to the guide rod; a motor operably coupled to the chain to drive the chain around the guide rod; a handle; a speed controller in communication with the motor to affect the motor speed; and a momentary switch, where the momentary switch limits actuation of the speed controller when the momentary switch is in a stationary state, where the momentary switch permits actuation of the speed controller when the momentary switch is in an activated state, where the momentary switch includes a base rotatably coupled to the handle and an articulated arm rotatably coupled to the base, and wherein the momentary switch is biased to a rest state.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 494,537, filed on April 6, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to chainsaws, and more particularly to safety features for chainsaws. Background Art

[0004] Chain saws utilize a moving chain having cutting teeth that are arranged to cut into material (such as wood) as the teeth are driven along the outer periphery of a guide rod. The teeth are driven along the outer periphery of the guide rod in an infinite, continuous manner by a drive element. The drive element is controlled by a trigger located on the handle of the chainsaw. When the operator engages the trigger, the speed of the drive element changes, thereby changing the speed of the cutting teeth relative to the material being cut. As the cutting teeth move faster, the operational hazard to the user controlling the chain saw also increases.

[0005] Therefore, there is a desire in the art to improve the safety features of chain saws. In particular, a chain saw that provides an easy-to-use safety feature would be advantageous. Utility Model Content

[0006] According to the present disclosure, various aspects and advantages of the present invention will be partially set forth in the following description, or may be apparent from the description, or may be understood through technical practice.

[0007] According to one embodiment, a chain saw is provided. The chain saw includes: a guide bar; a chain disposed about the guide bar and movable relative to the guide bar; a motor operably coupled to the chain to drive the chain about the guide bar; a handle; a speed controller in communication with the motor to affect a motor speed; and a momentary switch, wherein when the momentary switch is in a rest state, the momentary switch restricts actuation of the speed controller, wherein when the momentary switch is in an activated state, the momentary switch allows actuation of the speed controller, wherein the momentary switch includes a base rotatably coupled to the handle and an articulated arm rotatably coupled to the base, and wherein the momentary switch is biased to a rest state.

[0008] According to another embodiment, a momentary switch for a chain saw is provided. The momentary switch includes: a base configured to be rotatably coupled to a handle of the chain saw; an articulated arm rotatably coupled to the base; a first biasing element configured to bias the base to a first rotational position relative to the handle; and a second biasing element configured to bias the articulated arm to the first rotational position relative to the base.

[0009] According to another embodiment, a method of using a chain saw is provided. The method includes: applying a force to an articulated arm of the momentary switch to cause the momentary switch to reconfigure from a rest state to an intermediate state by rotating the articulated arm of the momentary switch relative to a base of the momentary switch; continuing to apply the force to the momentary switch to reconfigure the momentary switch from the intermediate state to an activated state; actuating a speed control after the momentary switch is reconfigured to the activated state; and maintaining the force on the momentary switch to maintain the momentary switch in the activated state, wherein the momentary switch is biased to the rest state.

[0010] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present technology and, together with the description, are used to explain the principles of the present technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The specification provides a comprehensive and achievable disclosure of the present invention with reference to the accompanying drawings, which is directed to a person skilled in the art and includes the best mode for making and using the present system and method, in which:

[0012] Figure 1 is a perspective view of a chain saw according to an embodiment of the present disclosure;

[0013] Figure 2 According to the embodiment of the present disclosure Figure 1 a top view of a portion of a handle of a chain saw (the portion including a momentary switch disposed in a stationary state);

[0014] Figure 3 According to the embodiment of the present disclosure Figure 1 The portion of the handle of the chain saw (the portion including the Figure 2 A top view of a momentary switch;

[0015] Figure 4 is a perspective view of a momentary switch in a stationary state according to an embodiment of the present disclosure;

[0016] Figure 5 is a cross-sectional side view of a portion of a handle (the portion including a momentary switch in a resting state) according to an embodiment of the present disclosure;

[0017] Figure 6 is a perspective view of a momentary switch in an intermediate state according to an embodiment of the present disclosure;

[0018] Figure 7 is a cross-sectional side view of a portion of a handle including a momentary switch in an intermediate state according to an embodiment of the present disclosure;

[0019] Figure 8 is a perspective view of a momentary switch in an activated state according to an embodiment of the present disclosure;

[0020] Fig. 9 is a cross-sectional side view of a portion of a handle including a momentary switch in an activated state according to an embodiment of the present disclosure;

[0021] Fig.10 is a perspective view of a momentary switch according to an embodiment of the present disclosure as viewed from an opposite side;

[0022] Fig.11 is a cross-sectional view of a portion of a handle having a momentary switch in a resting state according to an embodiment of the present disclosure; and

[0023] Fig.12 is a flow chart of a method of using a chain saw according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0024] The present invention will now be described in detail with reference to embodiments of the present invention, one or more examples of which are shown in the accompanying drawings. The word "exemplary" is used herein to mean "used as an example, instance or illustration". Any implementation described herein as "exemplary" is not necessarily interpreted as being more preferred or more advantageous than other implementations. In addition, each example is provided by way of explanation rather than limitation of the technology. In fact, it is obvious to those skilled in the art that modifications and changes may be made to the present technology without departing from the scope or spirit of the claimed technology. For example, a feature shown or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present disclosure is intended to cover such modifications and changes within the scope of the appended claims and their equivalents. Numerical and letter marks are used in the specific implementation to represent features in the drawings. Similar or similar marks in the drawings and the specification are used to refer to similar or similar parts in the present invention.

[0025] As used herein, the terms "first", "second" and "third" can be used interchangeably to distinguish one component from another, rather than to indicate the position or importance of a single component. The singular expressions "one", "an" and "the" also include plural cases, unless the context clearly dictates otherwise. Terms such as "coupled", "fixed", "connected to" refer to direct coupling, fixing or connection, as well as indirect coupling, fixing, or connection through one or more intermediate components or features, unless otherwise specified in the text. The terms "include", "comprise", "compose", "have" or any other variants thereof herein are intended to cover non-exclusive inclusion. For example, a process, method, article or device including a set of features is not necessarily limited to these features, but may include features that are not explicitly listed or other features inherent to such a process, method, article or device. In addition, unless there is a clear statement to the contrary, "or" is inclusive rather than exclusive. For example, any of the following satisfies conditions A or B: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0026] Terms indicating approximation, such as "about," "approximately," "approximately," or "substantially," include values ​​within 10% greater or less than the value being described. When used in the context of an angle or direction, these terms include values ​​within 10 degrees greater or less than the angle or direction being described. For example, "approximately perpendicular" includes directions that deviate from perpendicular within 10 degrees in any direction (e.g., clockwise or counterclockwise).

[0027] The benefits, other advantages and solutions to the problems are described below in conjunction with specific embodiments. However, the benefits, advantages, solutions to the problems and any features that may cause any benefit, advantage or solution to occur or become more obvious should not be construed as key, required or essential features of any or all claims.

[0028] In general, embodiments according to the present disclosure relate to features associated with a chainsaw that are configured to prevent the chainsaw from operating unless an operator maintains a sufficient grip on the chainsaw handle. The safety feature can be biased from an activated state to a static state. In the static state, the chainsaw is prevented from driving an infinite chain around a guide bar. In the activated state, the chainsaw can be operated so that the infinite chain can move around the guide bar to cut an object. The safety feature can include multiple pieces, such as two pieces, that are movably coupled together. The multiple pieces can form a large engagement area for the user to maintain the safety feature activated, thereby alleviating any undesirable pressure points on the user's hands during use, while at the same time providing a low profile and easy to interact design so that the user can easily grasp the safety feature to activate the safety feature and operate the chainsaw.

[0029] Now referring to the accompanying drawings, Figure 1A perspective view of a chain saw 100 according to an example embodiment is illustrated. The chain saw 100 is a motorized handheld power tool that includes a housing 102 in which a motor 104 is at least partially disposed. The motor 104 may include, for example, a direct current (DC) motor that receives power from a power source such as one or more removable batteries 106 (hereinafter referred to as batteries 106). The batteries 106 may be electrically connected to a logic device 108 such as a printed circuit board (PCB) that includes a control circuit that selectively provides power from the batteries 106 to the motor 104. The motor 104 may include an output shaft that is rotatably driven and interfaces with a drive gear to be operably connected to a chain 110. The chain 110 may move around a guide bar 112 and be driven infinitely by the motor 104 through the drive gear. Power supplied from the battery 106 to the motor 104 drives the chain 110 around a guide bar 112, thereby allowing the cutting teeth 114 of the chain 110 to remove material from the object being operated on, such as a log or tree.

[0030] The chain saw 100 may also include a handle 116 by which a user may grip and control the operation of the chain saw 100. The handle 116 may include control features such as a speed controller 118 (e.g., an actuable trigger) and a power selector 120 that may be moved between an on state and an off state to selectively connect and disconnect the motor 104 from the battery 106. To operate the chain saw 100, the power selector 120 is moved from the off state to the on state. Once the power selector 120 is moved to the on state, the user may interact with the speed controller 118 to change the drive speed of the chain 110 based on the relative position of the speed controller 118 between the non-drive speed (i.e., 0 RPM) and the maximum speed (e.g., set by the manufacturer and limited, for example, by the motor 104).

[0031] The guard 122 may be disposed between the handle 116 and the chain 110. The guard 122 may be movably mounted to the housing 102. The position of the guard 122 may be detected by a sensor in communication with the logic device 108 to affect control of the motor 104. If the chain saw 100 experiences a kickback (i.e., a rotational pulse that causes the chain saw 110 to move (rotate) toward the user), the guard 122 may hit the user (e.g., arm), causing the guard 122 to pivot from the use position to the braking position. When the logic device 108 receives a signal from the sensor 123 indicating that the guard 122 has been displaced, the logic device 108 terminates the power supply to the motor 104. In some implementations, the chain saw 100 may also include a brake (not shown) that quickly stops the movement of the chain 110, for example, in response to a kickback. This may be referred to as braking.

[0032] There is a commercial need for additional safety features to protect the user from kickback and other hazards associated with the movement of the cutting teeth 114. As described below, it is contemplated herein that the chain saw 100 may include a momentary switch that the user must maintain in an activated state to operate the chain saw 100, i.e., drive the chain 110 around the guide bar 112. The momentary switch may be normally open, for example, biased to a static state, thereby preventing the motor 104 from driving the chain 110. In order to activate the momentary switch, i.e., to drive the chain 110, the user must reposition the momentary switch from the static state to the activated state. In the activated state, the user can selectively engage the speed controller 118 and / or another control tool of the chain saw 100 to control the operation of the chain 110 and perform a cutting operation. The momentary switch automatically returns to the static state when released, thereby preventing operation of the chain saw 100 when the user releases the handle 116. In this regard, the momentary switch can prevent a user from accidentally driving the chain 110 when the user is not actively gripping the handle 116 or is gripping the handle 116 incorrectly (eg, with a weak grip).

[0033] In some examples, the momentary switch described below can replace the power selector 120. That is, the momentary switch can function as the power selector 120. In other examples, the momentary switch can be used in combination with the power selector 120 to control the chain saw 100. In such embodiments, the user must reconfigure the power selector 120 to the on state and move the momentary switch to the activated state to drive the chain 110. It should be understood that the embodiments described herein can be applicable to either or both configurations (i.e., further including or not including the power selector 120).

[0034] Figure 2 A portion of the handle 116 is illustrated as viewed from the top of the chain saw 100. As depicted, the handle 116 defines a grippable surface 124 that a user contacts when holding the chain saw 100 (e.g., with their hand). The user can wrap their hand around the grippable surface 124 to interact with the speed control 118. The speed control 118 can be located on the underside of the handle 116 so that the user can actuate the speed control 118 using their index and / or middle fingers. The handle 116 also includes a recessed portion 126 that extends from the surface 124 into the handle 116. The recessed portion 126 is formed in a manner similar to the embodiment of the chain saw 100. Figure 2 116 in a generally downward direction (e.g., toward Figure 1The recessed portion 126 extends from the motor 104 in the handle 116, however, it should be understood that the recessed portion 126 can be alternatively or additionally provided on another aspect of the handle 116, such as a side extending in the lateral direction of the handle 116. The recessed portion 126 can be provided at a conveniently accessible position of the handle 116 associated with the speed controller 118. In an embodiment, the recessed portion 126 is provided at a position where the user places his palm when holding the handle 116 to interact with the speed controller 118.

[0035] The size and shape of the recessed portion 126 can be designed to accommodate the momentary switch 128 in both the rest state and the activated state. Figure 2 , the momentary switch 128 is in a resting state. In the resting state, the momentary switch 128 extends (protrudes) from the recessed portion 126. In the resting state, the momentary switch 128 is only partially disposed within the recessed portion 126.

[0036] The momentary switch 128 may have a multi-piece construction including, for example, a base 130 and an articulated arm 132 movably coupled to the base 130 .

[0037] In an embodiment, the articulated arm 132 may be rotatably coupled to the base 130, for example, about an axis of rotation 134. The axis of rotation 134 may be formed by a pin 136 that interfaces with both the base 130 and the articulated arm 132. For example, the pin 136 may extend through an opening in each of the base 130 and the articulated arm 132 to provide a bearing surface therebetween. The articulated arm 132 may be rotationally biased toward a stationary state about the axis of rotation 134 by a biasing element 138, such as a torsion spring having a coil wrapped around the pin 136. The base 130 and the articulated arm 132 may each include a retaining feature, such as a channel, that receives and interfaces with an arm of the coil spring to recess the coil spring from contact with a user's fingers during use of the chain saw 100.

[0038] The base 130 is rotatably coupled to the housing 102 (or an internal frame or other support structure of the chain saw 100) via a pin 140. The base 130 can be rotated about a rotation axis 142 formed by the pin 140 to reposition the momentary switch 128 between an activated state and a rest state. A biasing element 144 (such as a torsion spring having a coil wrapped around the pin 140) can bias the base 130 to the rest state so that the momentary switch 128 functions as a normally open switch. For example, the torsion spring can include an arm that interfaces with the base 130 and the housing 102 (or other internal frame or support structure of the chain saw 100) to bias the base 130 to the rest state about the rotation axis 142.

[0039] In an embodiment, the rotation axes 134, 142 are oriented parallel to each other. The rotation axes 134, 142 may also be spaced apart from each other. The rotation axes 134, 142 may be oriented perpendicular to the length of the guide rod 112 ( Figure 1 ), such that rotation of base 130 relative to housing 102 and rotation of articulated arm 132 relative to base 130 causes momentary switch 128 to move in a plane oriented parallel to guide rod 112. In some examples, components of momentary switch 128 may only move in a direction along a plane oriented parallel to guide rod 112.

[0040] Figure 3 The diagram shows the process of rotating the base 130 from a stationary state about the rotation axis 142 ( Figure 2 ) is viewed in an activated state after rotation of the handle 116. The size and shape of the recessed portion 126 can be designed to at least partially accommodate the momentary switch 128 within the cutout of the handle 116 when the momentary switch 128 is in the activated state. In an embodiment, at least 50% of the momentary switch 128 is disposed within the volume of the recessed portion 126 when the momentary switch 128 is in the activated state, such as at least 75% of the momentary switch 128 is disposed within the volume of the recessed portion 126 when the momentary switch 128 is in the activated state, such as at least 90% of the momentary switch 128 is disposed within the volume of the recessed portion 126 when the momentary switch 128 is in the activated state, such as at least 95% of the momentary switch 128 is disposed within the volume of the recessed portion 126 when the momentary switch 128 is in the activated state, such as at least 99% of the momentary switch 128 is disposed within the volume of the recessed portion 126 when the momentary switch 128 is in the activated state.

[0041] Figures 4 to 9 The momentary switch 128 is illustrated in various states according to an example embodiment. In particular, Figure 4 and Figure 5 illustrates the momentary switch 128 in a resting state as viewed from a perspective view and a cross-sectional side view, respectively, according to an example embodiment; Figure 6 and Figure 7 illustrates the momentary switch 128 in an intermediate state as viewed from a perspective view and a cross-sectional side view, respectively, according to an example embodiment; and Figure 8 and Fig. 9 The momentary switch 128 is illustrated in an activated state as viewed from a perspective view and a cross-sectional side view, respectively, according to an example embodiment. As described below, the momentary switch 128 is configured to be moved by a user between a rest state, an intermediate state, and an activated state. Although the intermediate state is depicted and described as a single state of the momentary switch 128 between the rest state and the activated state, it should be understood that the intermediate state can refer to a transition position or a range of transition positions between the rest state and the activated state.

[0042] In some instances, placing the momentary switch 128 in the neutral state may have no effect on the operation of the chain saw 100. For example, moving the momentary switch 128 from the resting state to the neutral state may not affect the controllability of the chain saw 100. That is, the speed controller 118 may be restricted from moving even after the momentary switch reaches the neutral state. However, movement of the momentary switch 128 from the activated state to the neutral state may provide safety control as described herein with respect to the resting state. For example, once the momentary latch reaches the neutral state from the activated state, the speed controller 118 may be prevented from being actuated. Further movement of the momentary switch 128 from the neutral state to the resting state may not further affect the actuatability of the speed controller 118.

[0043] First reference Figure 4 and Figure 5 , the momentary switch 128 can be normally open so that the momentary switch 128 returns to the rest state when released by the user. As previously described, the biasing element 144 can bias the momentary switch 128 toward the rest state. In the rest state, the base 130 of the momentary switch 128 is in a first rotational position relative to the handle 116. The sidewall 146 of the recessed portion 126 can limit the rotation of the base 130 to the first rotational position. That is, the sidewall 146 can provide a stop surface against which the base 130 rests in the rest state.

[0044] The base 130 can be partially disposed within the interior volume 150 of the handle 116. For example, the base 130 can extend through the opening 148 of the recessed portion 126 of the handle 116. The opening 148 can be sealed to prevent contaminants, such as wood chips and debris, from entering the interior volume 150.

[0045] The handle 116 may define an upper surface 151 disposed along a line (or best fit line) 152 (hereinafter referred to as line 152). In an embodiment, the base 130 may be disposed on both sides of the line 152. For example, the base 130 may extend above the line 152 such that the rotation axis 134 is disposed at a vertical height above the line 152 and the rotation axis 142 is disposed at a vertical height below the line 152.

[0046] The articulated arm 132 can be rotatably coupled to the base 130 at a position above the line 152. In an embodiment, in a stationary state, the articulated arm 132 can be rotatably coupled to the base 130 in a rearward direction (ie, away from the guide rod 112 ( Figure 1)) extends. However, other arrangements and orientations of the articulated arm 132 (and even the momentary switch 128) are possible. The articulated arm 132 can have a surface and / or define a best fit line that extends in a direction generally parallel to the line 152. The gap 154 ​​can separate the articulated arm 132 from the grippable surface 124. The articulated arm 132 can also define a rounded end 156 or another gap-increasing feature that permits a user to reach between the articulated arm 132 and the grippable surface 124. The gap 154 ​​and the rounded end 156 (or other gap-increasing feature) can allow the user to more easily interact with the articulated arm 132 when repositioning the momentary switch 128 from a resting state. For example, a user can more easily grasp the momentary switch 128 (particularly the articulated arm 132) to reposition the momentary switch 128 from a resting state by moving their finger in the direction D and sliding under the articulated arm 132. The user can then move the articulated arm 132 to the position by rotating the articulated arm 132 in direction A about the rotation axis 134. Figure 6 and Figure 7 The intermediate position depicted in .

[0047] The articulated arm 132 defines a driving feature (such as the driving surface 158), and the base 130 defines a driven feature (such as the driven surface 160). In the static state, the driving surface 158 of the articulated arm 132 is disengaged from the driven surface 160 of the base 130. Therefore, the initial force applied to the articulated arm 132 in the direction A causes the relative displacement of the articulated arm 132 relative to the base 130. However, referring to Figure 6 and Figure 7 When the momentary switch 128 reaches the intermediate state, the drive surface 158 begins to drive (seat against) the driven surface 160, after which point further force applied to the articulated arm 132 in the direction A causes the base 130 to rotate about the rotation axis 142. However, if the user releases the articulated arm 132 in the intermediate state, the articulated arm 132 returns to the neutral position under the force provided by the biasing element 138. Figure 4 and Figure 5 The static state depicted in .

[0048] In an embodiment, momentary switch 128 may generate a tactile indication to the user when the intermediate state is reached by momentary switch 128. For example, when drive surface 158 contacts driven surface 160, the user may experience a tactile pulse transmitted through one or more portions of momentary switch 128. Additionally or alternatively, the user may hear an audible sound, such as a click, when drive surface 158 contacts driven surface 160. Other user indications may also occur to signal to the user that the intermediate state has been achieved.

[0049] Figure 8 and Fig. 9 The diagram shows how the articulated arm 132 reaches Figure 6 and Figure 7 150 and 154. The momentary switch 128 is viewed after further force is applied in direction A after the intermediate position depicted in . Applying further force in direction A can result in the momentary switch 128 reaching a second rotational position relative to the handle 116. The inner surface 161 of the interior volume 150 can act as a stop feature to limit the rotation of the momentary switch 128 at the second rotational position. Additionally or alternatively, the recessed portion 126 and / or one or more features disposed within the interior volume 150 can limit the rotation of the momentary switch 128. Although direction A is depicted as a rotational direction, it should be understood that instead of or in addition to a rotational force, a force can be applied in a linear direction, causing the momentary switch 128 to move (pivot) in the rotational direction depicted by arrow A.

[0050] In some examples, momentary switch 128 is moved from a rest state ( Figure 4 and Figure 5 ) moves to the intermediate state ( Figure 6 and Figure 7 ) can be compared to the force required to move the momentary switch 128 from the neutral state ( Figure 6 and Figure 7 ) moves to the active state ( Figure 8 and Fig. 9 ) are the same or substantially the same. For example, the biasing elements 138, 144 ( Figure 2 ) can be adjusted (e.g., selected) so that the force required to overcome the restoring force of biasing elements 138 and 144 is the same. In this regard, the user may not physically detect that momentary switch 128 reaches the intermediate state, but instead will experience the entire movement from the rest state to the activated state as a smooth, continuous rotational-translational movement. In other examples, moving momentary switch 128 from the rest state ( Figure 4 and Figure 5 ) moves to the intermediate state ( Figure 6 and Figure 7 ) may be different from the force required to move the momentary switch 128 from the neutral state ( Figure 6 and Figure 7 ) moves to the active state ( Figure 8 and Fig. 9 ) The force required. For example, where the biasing elements 138, 144 are torsion springs having the same spring constant, the location of the force applied to the momentary switch 128 has a different displacement length from the axis of rotation 134, 142, resulting in a different force requirement.

[0051] In the activated state, the momentary switch 128 can have (exhibit) a low profile configuration, protruding only minimally (or not at all) above the line 152. In this regard, the momentary switch 128 can feel like a continuation of the upper surface 151 of the handle 116 in the activated state. The user can place their hand (such as their palm) on the momentary switch 128 to maintain the momentary switch 128 in the activated state. However, when the user releases their hand from the handle 116, the momentary switch 128 immediately returns to the rest position unless the user takes action to prevent such movement (such as grabbing the momentary switch 128 when the momentary switch 128 is rotated in the direction opposite to the direction A or otherwise restricting the movement of the momentary switch 128). Therefore, the momentary switch 128 remains in the activated state only during the time when the user is actively controlling the chain saw 100 with their hand on the handle 116.

[0052] As described above, the momentary switch 128 can provide additional safety for the user, thereby preventing operation of the chain saw 100 when the user fails to maintain the momentary switch 128 in an activated state. In an embodiment, the momentary switch 128 can interact with the speed controller 118. More specifically, when the momentary switch 128 is in a static state, the momentary switch 128 can prevent the user from actuating the speed controller 118 to drive the motor 104 ( Figure 1 ). In addition, when the momentary switch 128 is in the neutral state, the momentary switch 128 may also prevent the user from actuating the speed controller 118 to drive the motor 104. However, once the momentary switch 128 reaches the activated state, the speed controller 118 may be actuatable, thereby allowing the user to activate the motor 104 and drive the chain 110 ( Figure 1 ).

[0053] The relative position of the momentary switch 128 can be determined by the sensor 157 ( Figure 1 ) detection. Sensor 157 may include a contact switch, an optical sensor, a pressure pad, an electrical sensor (such as a conductive sensor), etc. Sensor 157 may communicate with logic device 108 via one or more wired connections or wireless communication protocols. Logic device 108 may provide a signal to logic device 108 that includes information about momentary switch 128, and more particularly information about the relative position of momentary switch 128. Sensor 157 may notify logic device 108 when momentary switch 128 is in one or more of the states described above. In this regard, logic device 108 may adjust the operating conditions of motor 104 or even activate a brake to stop the movement of chain 110.

[0054] The following description provides an example embodiment of the interaction of the momentary switch 128 with the speed controller 118. It should be understood that the momentary switch 128 and / or the speed controller 118 may be altered or adjusted to accommodate different interaction arrangements therebetween.

[0055] refer to Figure 5 and Figure 7 , the base 130 of the momentary switch 128 can define a locking surface 162. The locking surface 162 can have an arcuate profile. In an embodiment, the arcuate profile of the locking surface 162 can define a radius of curvature centered on the rotation axis 142. When the momentary switch 128 is moved in direction A from the neutral state ( Figure 6 and Figure 7 ) moves to the active state ( Figure 8 and Fig. 9 ), the locking surface 162 can move in direction B. The speed controller 118 can have a complementary locking surface 164 that is configured to interface with the locking surface 162 to lock the speed controller 118 when the momentary switch 128 is in a stationary state. In an embodiment, the complementary locking surface 164 can have an arcuate profile, e.g., the same or substantially similar to the arcuate profile of the locking surface 162. For example, the arcuate profile of the complementary locking surface 164 can define a radius of curvature centered on the rotation axis 142. In this regard, the locking surface 162 can slide past (along) the complementary locking surface 164 while limiting (e.g., preventing) movement of the speed controller 118 until the locking surface 162 disengages from the complementary locking surface 164. In some instances, a small gap can exist between the locking surface 162 and the complementary locking surface 164 to facilitate easier relative sliding between the two surfaces.

[0056] When the momentary switch 128 moves from the neutral state to the activated state, the locking surface 162 of the momentary switch 128 disengages the complementary locking surface 164 of the speed controller 118. It should be noted that the locking surface 162 may be disengaged when reaching the Fig. 9 Once the complementary locking surface 164 is disengaged from the locking surface 162 (e.g., Fig. 9 ), the speed controller 118 can be moved in the activation direction C (e.g., around Fig. 9 The pivot axis (not depicted in FIG. 1 ) is displaced to affect the state and speed of the motor 104 ( Figure 1 In implementations where the speed controller 118 affects the variable speed motor 104, the further the speed controller 118 is displaced, the greater the speed of the motor 104 (until a maximum operating speed is reached).

[0057] When the user is finished using the chain saw 100, the user can release the momentary switch 128, causing the locking surface 162 to move in a direction opposite to direction B ( Figure 5 and Figure 7 In some examples, the speed controller 118 may still be actuated in direction C ( Fig. 9). In such examples, the momentary switch 128 may remain in a position between the activated state and the rest state until the speed controller 118 returns to its rest position (in a direction opposite to direction C). More specifically, the speed controller 118 may prevent the momentary switch 128 from returning to the rest state. However, in the case where the speed controller 118 is not actuated in direction C and is in the rest position ( Figure 5 and Figure 7 ), the momentary switch 128 can return to a resting state wherein the locking surface 162 moves (slides) past the complementary locking surface 164 to limit (prevent) actuation of the speed controller 118. Thus, by releasing the momentary switch 128, the user is prevented from accidentally re-actuating the speed controller 118.

[0058] Fig.10 The diagram shows the Figures 4 to 9 150. In an embodiment, the momentary switch 128 may be asymmetrical about a center plane 166 that bisects the momentary switch 128. For example, the momentary switch 128 may include a cutout feature 168 that accommodates internal structure of the handle 116, such as one or more posts or internal brackets (not shown) extending between opposite sides of the handle 116 in the interior volume 150. The cutout feature 168 may interact with the one or more posts or internal brackets to control aspects of the momentary switch 128. For example, the interior volume 150 may define a post that interacts with the cutout feature 168 to define the movement of the momentary switch 128. The cutout feature 168 may also or alternatively provide a surface against which the biasing element(s) 138, 144 may be placed. Additionally, the cutout feature 168 may provide a weight reduction benefit by reducing the mass of the momentary switch 128. The reduced mass can reduce inertia and facilitate faster displacement of the momentary switch 128 between the activated state and the rest state, thereby rendering the chain saw 100 inoperable more quickly when the user releases the momentary switch 128. In some examples, at least one of the pins 136, 140 can be integral with the momentary switch 128. For example, the base 130 can define a protrusion 170 that extends away from the base 130, such as from a position within the cutout 168, and the momentary switch 128 can be rotatable about the protrusion 170. The protrusion 170 can engage with the opening 172 ( Fig.11 ) docking to provide a pivot axis for the protrusion 170 and the base 130.

[0059] Fig.12 A flow chart of a method 1200 of using a chain saw according to an embodiment is illustrated. In general, reference will be made to the Figures 1 to 11The method 1200 is described with reference to the chain saw with the features described and illustrated (such as the momentary switch 128). In addition, although for the purposes of illustration and discussion, Fig.12 The steps are depicted as being performed in a particular order, but unless otherwise specified, the methods discussed herein are not limited to any particular order or arrangement. Using the disclosure provided herein, those skilled in the art will appreciate that the various steps of the methods disclosed herein may be omitted, rearranged, combined and / or modified in various ways without departing from the scope of the present disclosure.

[0060] Method 1200 may include applying 1202 a force to an articulated arm of a momentary switch by rotating the articulated arm relative to the base of the momentary switch to cause the momentary switch to reconfigure from a static state to an intermediate state. The force may be applied 1202 directly to the articulated arm, such as at the rounded end of the articulated arm. The force 1202 may be applied to rotate the articulated arm relative to the base by at least 1°, such as at least 5°, such as at least 10°, such as at least 20°, such as at least 30°, such as at least 40°, such as at least 50°, such as at least 60°, such as at least 70°, such as at least 80°, or even such as at least 90°. The force applied in step 1202 must be large enough to overcome the biasing force that biases the articulated arm to a static state. For example, the biasing force may be adjusted by selecting between different biasing elements each having a different spring constant.

[0061] A force 1202 may be applied until the drive surface of the articulated arm contacts the driven surface of the base. At this point, the user may experience a tactile or audible indication to the user that the momentary switch is in an intermediate state.

[0062] The method 1200 may also include continuing to apply 1204 a force to the momentary switch to reconfigure the momentary switch from the intermediate state to the activated state. In an embodiment, the force applied at step 1204 may be applied in the same manner as the force applied at step 1202, for example, the force may be applied 1204 to the articulated arm. In such a manner, when switching between steps 1202 and 1204, the user may not be required to reconfigure their hand relative to the momentary switch. In fact, the continued application of force 1204 may not include a discrete application of force separate from the force applied at step 1202. That is, for example, the force applied at step 1204 may be a continuation of the force applied at step 1202. In some instances, the force applied at step 1204 may be different from the force applied at step 1202. For example, the force applied at step 1204 may be greater than the force applied at step 1202. This may allow the base to remain in a relatively fixed position when the momentary switch is switched to the intermediate state. In other examples, the force applied at step 1204 may be the same as the force applied at step 1202 .

[0063] The force applied at step 1204 may cause the base to rotate about the axis of rotation by a displacement of at least 1° (such as at least 10°, such as at least 20°, such as at least 30°, such as at least 40°, such as at least 50°, such as at least 60°, such as at least 70°, such as at least 80°, or even such as at least 90°). In some implementations, during the application of the force at step 1204, the articulated arm may remain static relative to the base. That is, during the application of the force at step 1204, the base and the articulated arm may move together (that is, remain relatively fixed in space relative to each other). The force may be applied at step 1204 until the momentary switch reaches the activated state. Before the momentary switch reaches the activated state, the speed controller of the chain saw may be restricted (e.g., prevented) from being actuated by the user. In this regard, the user may not be able to operate the chain saw (at least at full operating power). In an embodiment, the movement of the speed controller may be restricted by the momentary switch until the momentary switch reaches the activated state.

[0064] The method 1200 may also include actuating 1206 the speed controller after the momentary switch is reconfigured to the activated state. At this point, the momentary switch disengages the speed controller, thereby allowing the speed controller to shift (e.g., rotate about the pivot axis) from a minimum operating speed to a maximum operating speed. The operator may actuate 1206 the speed controller a desired amount to affect the speed control of the motor and thereby drive the chain at a desired speed.

[0065] The method 1200 may also include maintaining 1208 a force on the momentary switch to maintain the momentary switch in an activated state, wherein the momentary switch is biased to a stationary state, for example, by a torsion spring (such as a torsion spring of a base biasing the momentary switch). Maintaining 1208 a force on the momentary switch may be performed by the user's hand firmly holding the handle of the chain saw. For example, the user may wrap their palm around the handle and rely on their index finger (and / or middle finger) to operate the speed controller. At the same time, the user's palm may be placed against the momentary switch to provide a force to counteract the biasing force that attempts to move the momentary switch to the stationary state. As long as the user maintains 1208 a force on the momentary switch, operation of the speed controller is permitted. However, releasing the force from the momentary switch may provide an opportunity for the momentary switch to return to the stationary state, after which the speed controller may be again restricted (e.g., locked) in an unactuated (unpowered) state. In some examples, the braking system of the chain saw may be engaged in response to the momentary switch moving from the activated state to the stationary state.

[0066] It should be understood that the embodiments described herein do not allow a user to actuate the speed controller of a chainsaw when the user does not have a sufficient grip on the handle. By ensuring that the user has a sufficient grip on the handle to allow movement of the speed controller, the user is less likely to be in a dangerous position where the cutting teeth could injure the user. For example, a user cannot initiate movement of the cutting teeth while a blade sharpening operation is being performed while the battery is still electrically coupled to the chainsaw. Additionally, the force required to maintain the momentary switch in an activated state may require a firm grip on the chainsaw. Thus, the operator cannot use the chainsaw without a firm grip on the handle, and any loss of grip may cause the chainsaw to fail.

[0067] The embodiments described herein provide mechanical resistance to improper and / or unsafe use. Although electrical safety controls can be implemented (e.g., communicating the state of the momentary switch to a logic device relative to sensor 157 as described above), it is contemplated herein that the momentary switch forms a mechanical interference that prevents the speed controller from being actuated when the user does not maintain the momentary switch in an activated state. In some instances, the use of redundant electrical controls (e.g., using sensor 157 to detect the position of the momentary switch) can provide additional safety to the user, however, electrical controls may be affected by power spikes, line shorts, etc., and it is believed that mechanical safety features (alone or in combination with electrical controls) can provide additional safety to the user.

[0068] Further aspects of the present invention are provided by one or more of the following embodiments:

[0069] Embodiment 1. A chain saw comprising: a guide bar; a chain disposed about the guide bar and movable relative to the guide bar; a motor operably coupled to the chain to drive the chain about the guide bar; a handle; a speed controller communicating with the motor to affect a motor speed; and a momentary switch, wherein when the momentary switch is in a stationary state, the momentary switch limits actuation of the speed controller, wherein when the momentary switch is in an activated state, the momentary switch allows actuation of the speed controller, wherein the momentary switch comprises a base rotatably coupled to the handle and an articulated arm rotatably coupled to the base, and wherein the momentary switch is biased to a stationary state.

[0070] Embodiment 2. A chainsaw according to embodiment 1, wherein the base of the momentary switch is rotatable relative to the handle about a first rotation axis, wherein the articulated arm is rotatable relative to the base about a second rotation axis, and wherein the first rotation axis and the second rotation axis are oriented parallel to each other.

[0071] Embodiment 3. The chain saw of Embodiment 2, wherein the base is rotatably biased about a first rotational axis by a first torsion spring, and wherein the articulated arm is rotatably biased about a second rotational axis by a second torsion spring.

[0072] Embodiment 4. The chain saw of any of Embodiments 1 or 2, wherein the base defines a locking surface having an arcuate profile having a radius of curvature disposed at the first axis of rotation.

[0073] Embodiment 5. The chain saw of Embodiment 4, wherein the speed controller defines complementary locking surfaces that interfere with the locking surface when the momentary switch is in the rest state.

[0074] Embodiment 6. A chainsaw according to any of the preceding embodiments, wherein the handle includes a recessed portion extending from the grippable surface into the handle, and wherein the momentary switch is at least partially disposed within the recessed portion in both the rest state and the activated state.

[0075] Embodiment 7. The chain saw of Embodiment 6, wherein at least 90% of the momentary switch is contained within the volume defined by the recessed portion when the momentary switch is in an activated state.

[0076] Embodiment 8. The chain saw of any of the preceding embodiments, wherein the articulated arm includes a drive surface, wherein the base includes a driven surface, and wherein the drive surface contacts the driven surface when the momentary switch is reconfigured from the rest state to the intermediate state.

[0077] Embodiment 9. A chainsaw according to any of the preceding embodiments, wherein the articulated arm is disposed above an upper surface of the handle when the momentary switch is in a rest state, and wherein a majority of the articulated arm is disposed below the upper surface of the handle when the momentary switch is in an articulated state.

[0078] Embodiment 10. A momentary switch for a chain saw, the momentary switch comprising: a base configured to be rotatably connected to a handle of the chain saw; an articulated arm rotatably connected to the base; a first biasing element configured to bias the base to a first rotational position relative to the handle; and a second biasing element configured to bias the articulated arm to the first rotational position relative to the base.

[0079] Embodiment 11. A momentary switch as described in Embodiment 10, wherein the base is configured to be rotatably connected to the handle about a first rotation axis, wherein the articulated arm is rotatably connected to the base about a second rotation axis, and wherein the first rotation axis and the second rotation axis are parallel to each other.

[0080] Embodiment 12. The momentary switch of Embodiment 11, wherein the base includes a cutout portion and a protrusion protruding from a side surface of the cutout portion, the protrusion being identified to form a first rotation axis of the base relative to the handle.

[0081] Embodiment 13. A momentary switch according to any of Embodiments 10 or 11, wherein the base includes an arcuate locking surface configured to interfere with a complementary locking surface of a speed controller of the chain saw, and wherein a radius of curvature of the arcuate locking surface is disposed at the first rotational axis.

[0082] Embodiment 14. A momentary switch as described in any one of embodiments 10 to 13, wherein the articulated arm defines a driving surface, wherein the base defines a driven surface, wherein the driving surface is configured to bias the driven surface when a force is applied to the articulated arm, wherein the driving surface is disengaged from the driven surface when the momentary switch is in a static state, and wherein the driving surface is docked with the driven surface when the momentary switch is in an intermediate state and an activated state.

[0083] Embodiment 15. A momentary switch according to any one of embodiments 10 to 14, wherein the momentary switch is configured to be repositionable between a rest state and an activated state, wherein the momentary switch is configured to limit actuation of a speed controller in the rest state and to permit actuation of the speed controller in the activated state, and wherein the momentary switch is biased to the rest state by a first biasing element.

[0084] Embodiment 16. A method of using a chain saw, the method comprising: applying a force to an articulated arm of a momentary switch by rotating the articulated arm relative to a base of the momentary switch to cause the momentary switch to reconfigure from a rest state to an intermediate state; continuing to apply force to the momentary switch to reconfigure the momentary switch from the intermediate state to an activated state; actuating a speed controller after the momentary switch is reconfigured to the activated state; and maintaining the force on the momentary switch to maintain the momentary switch in the activated state, wherein the momentary switch is biased to a rest state.

[0085] Embodiment 17. The method of Embodiment 16, wherein applying a force that causes the momentary switch to reconfigure from the rest state to the intermediate state causes the driving surface of the articulated arm to contact the driven surface of the base.

[0086] Embodiment 18. The method of any one of Embodiments 16 or 17, further comprising releasing the momentary switch, wherein releasing the momentary switch causes the momentary switch to reconfigure to a rest state.

[0087] Embodiment 19. A method according to any one of Embodiments 16 to 18, wherein reconfiguring the momentary switch from a rest state to an intermediate state is performed by rotating the articulated arm about a first rotation axis, wherein reconfiguring the momentary switch from the intermediate state to an activated state is performed by rotating the articulated arm about a second rotation axis, and wherein the first rotation axis and the second rotation axis are spaced apart from each other.

[0088] Embodiment 20. The method of Embodiment 19, wherein the first rotation axis and the second rotation axis are oriented parallel to each other.

[0089] This specification uses examples to disclose the utility model, including the best mode, and enables any technician in the field to practice the utility model, including making and using any device or system and performing any combined method. The patent scope of the utility model is defined by the claims and may include other examples that can be thought of by those skilled in the art. If these other examples include structural elements that are not different from the literal wording of the claims, or include equivalent structural elements that are not substantially different from the literal wording of the claims, the scope of the claims covers these other examples.

Claims

1. A chain saw, characterized in that: The chain saw comprises: Guide rod; a chain disposed around the guide rod and movable relative to the guide rod; a motor operably coupled to the chain to drive the chain about the guide rod; handle; a speed controller in communication with the motor to affect motor speed; and A momentary switch, wherein when the momentary switch is in a resting state, the momentary switch restricts actuation of the speed control, wherein when the momentary switch is in an activated state, the momentary switch allows actuation of the speed control, wherein the momentary switch includes a base rotatably coupled to the handle and an articulated arm rotatably coupled to the base, and wherein the momentary switch is biased to the resting state.

2. The chain saw according to claim 1, characterized in that The base of the momentary switch is rotatable relative to the handle about a first rotation axis, wherein the articulated arm is rotatable relative to the base about a second rotation axis, and wherein the first rotation axis and the second rotation axis are oriented parallel to each other.

3. The chain saw according to claim 2, characterized in that The base is rotatably biased about a first rotational axis by a first torsion spring, and wherein the articulated arm is rotatably biased about a second rotational axis by a second torsion spring.

4. The chain saw according to claim 2, characterized in that: The base defines a locking surface having an arcuate profile with a radius of curvature disposed at a first axis of rotation.

5. The chain saw according to claim 4, characterized in that The speed controller defines a complementary locking surface that interferes with the locking surface when the momentary switch is in the rest state.

6. The chain saw according to claim 1, characterized in that The handle includes a recessed portion extending from a grippable surface into the handle, and wherein the momentary switch is at least partially disposed within the recessed portion in both the rest state and the activated state.

7. The chain saw according to claim 6, characterized in that When the momentary switch is in the activated state, at least 90% of the momentary switch is contained within a volume defined by the recessed portion.

8. The chain saw according to claim 1, characterized in that The articulated arm includes a drive surface, wherein the base includes a driven surface, and wherein the drive surface contacts the driven surface when the momentary switch is reconfigured from the rest state to an intermediate state.

9. The chain saw according to claim 1, characterized in that The articulated arm is disposed above an upper surface of the handle when the momentary switch is in the rest state, and wherein a majority of the articulated arm is disposed below an upper surface of the handle when the momentary switch is in the activated state.

10. A momentary switch for a chain saw, characterized in that: The momentary switch comprises: a base configured to be rotatably coupled to a handle of the chain saw; an articulated arm rotatably coupled to the base; a first biasing element configured to bias the base to a first rotational position relative to the handle; and A second biasing element is configured to bias the articulated arm to a first rotational position relative to the base.

11. The momentary switch according to claim 10, characterized in that The base is configured to be rotatably coupled to the handle about a first rotational axis, wherein the articulated arm is rotatably coupled to the base about a second rotational axis, and wherein the first rotational axis and the second rotational axis are parallel with respect to each other.

12. The momentary switch according to claim 11, characterized in that The base includes a cutout portion and a protrusion protruding from a side surface of the cutout portion, the protrusion being identified to form a first rotation axis of the base relative to the handle.

13. The momentary switch of claim 11, wherein: The base includes an arcuate locking surface configured to interfere with a complementary locking surface of a speed control of the chain saw, and wherein a radius of curvature of the arcuate locking surface is disposed at the first axis of rotation.

14. The momentary switch of claim 10, wherein: The articulated arm defines a drive surface, wherein the base defines a driven surface, wherein the drive surface is configured to bias the driven surface when a force is applied to the articulated arm, wherein the drive surface is disengaged from the driven surface when the momentary switch is in a rest state, and wherein the drive surface engages the driven surface when the momentary switch is in an intermediate state and an activated state.

15. The momentary switch of claim 10, wherein: The momentary switch is configured to be repositionable between a rest state and an activated state, wherein the momentary switch is configured to restrict actuation of the speed controller in the rest state and permit actuation of the speed controller in the activated state, and wherein the momentary switch is biased to the rest state by a first biasing element.

16. A chain saw, characterized in that: The chain saw comprises: Guide rod; a chain disposed around the guide rod and movable relative to the guide rod; a motor operably coupled to the chain to drive the chain about the guide rod; handle; a speed controller in communication with the motor to affect motor speed; and a momentary switch, wherein when the momentary switch is in a resting state, the momentary switch restricts actuation of the speed control, wherein when the momentary switch is in an activated state, the momentary switch allows actuation of the speed control, wherein the momentary switch includes a base rotatably coupled to the handle and an articulated arm rotatably coupled to the base, and wherein the momentary switch is biased to the resting state, Wherein, the chain saw is operated in the following manner: applying a force to the momentary switch by rotating the articulated arm relative to the base to cause the momentary switch to reconfigure from the rest state to an intermediate state; continuing to apply force to the momentary switch to reconfigure the momentary switch from the intermediate state to the activated state; actuating the speed controller after the momentary switch is reconfigured to an activated state; and A force is maintained on the momentary switch to maintain the momentary switch in the activated state, wherein the momentary switch is biased to the rest state.

17. The chain saw according to claim 16, characterized in that Applying a force that causes the momentary switch to reconfigure from the rest state to the intermediate state causes the drive surface of the articulated arm to contact the driven surface of the base.

18. The chain saw according to claim 16, characterized in that The chain saw also includes releasing the momentary switch, wherein releasing the momentary switch causes the momentary switch to reconfigure to the rest state.

19. The chain saw according to claim 16, characterized in that Reconfiguring the momentary switch from the rest state to the intermediate state is performed by rotating the articulated arm about a first rotational axis, wherein reconfiguring the momentary switch from the intermediate state to the activated state is performed by rotating the articulated arm about a second rotational axis, and wherein the first rotational axis and the second rotational axis are spaced apart from each other.

20. The chain saw according to claim 19, characterized in that The first rotation axis and the second rotation axis are oriented parallel to each other.

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