Electric work machine

Abstract

To easily recognize an operation state of a lock member of a switch operation member of an electric work machine.SOLUTION: An electric work machine includes a motor, a switch, a switch operation member, a lock member, a housing, a first contact part, and a second contact part. The housing has an opening for exposing the operation part of the lock member so as to be press-operable from outside. The first contact part and the second contact part are provided so as to be adjacent to the opening. The operation part projects to outside a virtual plane in contact with the first contact part and the second contact part when the lock member is at a lock-off position, and is inside the plane when the lock member is at a lock-on position. The lock release position is set between the lock-off position and the lock-on position. The first contact part and the second contact part are configured so as to be brought into contact with fingers of a user, and thereby regulate pressing operation of moving the lock member from the lock release position to the lock-on position.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a power working machine. More specifically, it relates to a power working machine provided with a lock member capable of regulating the movement of a switch operation member from an off position to an on position and the movement of the switch operation member from the on position to the off position.

Background Art

[0002] A power working machine includes a switch for starting a motor and a switch operation member (for example, a switch lever, a trigger) movable between an off position and an on position for switching the on / off state of the switch. Further, for improving convenience, a power working machine provided with a lock mechanism capable of regulating the movement of the switch operation member from the off position to the on position and the movement of the switch operation member from the on position to the off position is known. For example, Patent Document 1 discloses a lawn mower provided with a lock button capable of regulating the movement of a switch lever from the off position to the on position and the movement of the switch lever from the on position to the off position.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A user of the lawn mower of Patent Document 1 cannot easily recognize the position of the lock button when operating the lock button. Therefore, the user has to carefully operate the lock lever to hold the switch lever in the on position with respect to the lock button.

[0005] In view of the above situation, one non-limiting object of the present disclosure is to make it easier to recognize the operation state of the lock member of the switch operation member of the power working machine. [Means for solving the problem]

[0006] According to one non-limiting aspect of the present disclosure, an electric work machine is provided comprising a motor, a switch, a switch operating member, a locking member, a housing, a first contact portion, and a second contact portion.

[0007] The switch is a switch for starting the motor. The switch operating member is movable between an off position, which turns the switch off, and an on position, which turns the switch on, in response to manual operation by the user. The locking member has an operating part. The locking member is supported so as to be movable from the lock-off position to the lock-on position, via an unlock position, in response to a user's pressing operation on the operating part. In the unlock position, the locking member allows movement of the switch operating member between the off position and the on position. In the lock-off position, the locking member can restrict movement of the switch operating member from the off position to the on position. In the lock-on position, the locking member can restrict movement of the switch operating member from the on position to the off position.

[0008] The housing has an opening that exposes the operating portion of the locking member so that it can be pressed from the outside. The first and second contact portions are located adjacent to the opening so that the user can touch them with their fingers. When the locking member is in the lock-off position, the operating portion protrudes outward from a virtual plane that is in contact with the first and second contact portions. When the locking member is in the lock-on position, the operating portion is inward from the plane. The unlock position is set between the lock-off position and the lock-on position. The first and second contact portions are configured so that contact with the user's fingers restricts the pressing operation that moves the locking member from the unlock position to the lock-on position.

[0009] According to the electric work machine of this embodiment, the user can easily recognize that the locking member is in the lock-off position by touching at least one of the first contact portion and the second contact portion located adjacent to the opening, and the operating portion of the locking member. Furthermore, when the user's fingers come into contact with the first contact portion and the second contact portion, the user can easily recognize that in order to move the locking member from the unlocked position to the lock-on position, it is necessary to move the fingers and press the locking member. Thus, the possibility of the user unconsciously moving the locking member to the lock-on position can be reduced. In this way, the electric work machine of this embodiment enables the user to easily recognize the operating state of the locking member through touch. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of a belt sander according to the first embodiment. [Figure 2] This is a right side view of the belt sander. [Figure 3] This is a left side view of the belt sander. [Figure 4] This is a cross-sectional view of a belt sander. [Figure 5] This is a partial right-side view of a belt sander with the main housing and the right half of the handle housing removed. [Figure 6] This is a perspective view of the switch lever and the first lock button. [Figure 7] Another perspective view of the switch lever and the first lock button. [Figure 8] This is a cross-sectional view along line VIII-VIII in Figure 2. [Figure 9] This diagram illustrates the positional relationship between the first lock button and the switch lever when the first lock button is in the lock-off position. [Figure 10] This diagram illustrates the positional relationship between the first lock button and the switch lever when the lock button is in the unlocked position. [Figure 11] This diagram illustrates the positional relationship between the first lock button and the switch lever when the first lock button is in the lock-on position. [Figure 12]It is an explanatory diagram of the positional relationship between the first contact portion, the second contact portion, and the concave portion when the first lock button is in the unlock position, the unlock release position, and the lock-on position. [Figure 13] It is an explanatory diagram of the first contact portion, the second contact portion, and the concave portion according to the second embodiment. [Figure 14] It is an explanatory diagram of the first contact portion, the second contact portion, and the concave portion according to the third embodiment. [Figure 15] It is an explanatory diagram of the first contact portion, the second contact portion, and the concave portion according to the fourth embodiment.

Mode for Carrying Out the Invention

[0011] In a non-limiting embodiment of the present disclosure, the lock member may be configured to be disposed at the unlock position in response to at least a part of the operation portion being disposed inside the plane. According to this embodiment, the lock member can be disposed at the unlock position substantially corresponding to the user pressing the lock member until the finger contacts the first contact portion and the second contact portion. Therefore, the user can easily recognize through the sense of touch that the lock member is disposed at the unlock position.

[0012] In addition to or instead of the above embodiment, at least one of the first contact portion and the second contact portion may be a protruding portion protruding from the outer surface of the housing. According to this embodiment, the user can easily recognize at least one of the first contact portion and the second contact portion through vision and touch.

[0013] In addition to or instead of the above embodiment, the first contact portion may be a protruding portion, and the second contact portion may be a part of the outer surface of the housing. According to this embodiment, the user can use a portion of the outer surface of the housing where it is easy to place a finger as the second contact portion.

[0014] In addition to or instead of the above-described embodiment, the first contact portion may be formed integrally with the housing. According to this embodiment, the number of components can be reduced and the manufacturing is also easy as compared with the case where the first contact portion is formed of a member separate from the housing.

[0015] In addition to or instead of the above-described embodiment, the locking member may be supported by the housing. According to this embodiment, the support structure of the locking member can be simplified as compared with the case where the locking member is supported by a separate member from the housing.

[0016] In addition to or instead of the above-described embodiment, the power-operated work machine may further include a recess provided adjacent to the opening and in which a part of a user's finger can be placed. According to this embodiment, the user can easily move the locking member from the unlock position to the lock-on position by placing a finger in the recess and pressing the operation portion.

[0017] In addition to or instead of the above-described embodiment, the recess may be recessed from the outer surface of the housing and defined by a curved surface. According to this embodiment, a recess that is easy to guide a finger and has a good touch feeling is realized.

[0018] In addition to or instead of the above-described embodiment, at least a part of the first contact portion and the recess may face each other across the opening in a direction orthogonal to the moving direction of the locking member. According to this embodiment, it becomes easy for the user to shift a finger into the recess and further press the locking member.

[0019] In addition to, or in place of, the above embodiment, the housing may include a grip portion configured to be held by the user. The switch operating member and the locking member may be positioned so that they can be operated by the user's index finger and thumb, respectively, while the user is holding the grip portion. According to this embodiment, the user can operate the switch operating member and the locking member with the index finger and thumb of one hand that is holding the grip portion, thus providing greater convenience.

[0020] Hereinafter, a representative and non-limiting first embodiment of the belt sander 1 of this disclosure will be specifically described with reference to the drawings. The belt sander 1 is an example of an electric work machine, and is an electric tool configured to polish a workpiece pressed against an endless sanding belt 27.

[0021] First, the general configuration of the belt sander 1 will be described. As shown in Figures 1 to 4, the outer casing of the belt sander 1 is formed by a housing 10. The housing 10 includes a main body housing 11 and a handle housing 15.

[0022] The main housing 11 is a hollow box-shaped body. As shown in Figure 4, the main housing 11 houses an electric motor 21, a power transmission mechanism 23, and a controller 29. The power transmission mechanism 23 is operably connected to the output shaft 211 of the motor 21 and the drive roller 25, and is configured to transmit the rotation of the output shaft 211 to the drive roller 25. The controller 29 is configured to control the operation of the belt sander 1.

[0023] The drive roller 25 is configured to rotate around axis A1 in conjunction with the drive of the motor 21. The sanding belt 27 is stretched between the drive roller 25 and the driven roller 26. The driven roller 26 is supported so as to be rotatable around axis A2, which is parallel to axis A1. The drive roller 25 and the driven roller 26 are spaced apart in directions perpendicular to axes A1 and A2. The sanding belt 27 rotates in one direction (in the direction of arrow R in Figure 4) in response to the rotational drive of the drive roller 25. A portion of the sanding belt 27 is exposed to the outside from the main housing 11 and extends along a plane that is roughly parallel to axes A1 and A2. This exposed portion of the sanding belt 27 is pressed by the plate 113 toward the workpiece (outward direction of the ring of the sanding belt 27).

[0024] For the sake of explanation, in the following, the direction in which the drive roller 25 and the driven roller 26 are aligned (i.e., the direction perpendicular to axes A1 and A2) will be defined as the front-rear direction of the belt sander 1. In the front-rear direction, the side with the drive roller 25 will be defined as the rear side, and the side with the driven roller 26 will be defined as the front side. Furthermore, the direction in which axes A1 and A2 extend will be defined as the left-right direction of the belt sander 1. Furthermore, the direction perpendicular to the front-rear direction and the left-right direction will be defined as the up-down direction of the belt sander 1. In the up-down direction, the side with the exposed portion of the sanding belt 27 will be defined as the lower side, and the opposite side will be defined as the upper side.

[0025] As shown in Figures 1 to 4, the handle housing 15 is generally a cylindrical body with a C-shape. Both ends of the handle housing 15 are connected to the upper rear end and lower rear end of the main housing 11, respectively, and the handle housing 15 and the rear end of the main housing 11 form a loop. The handle housing 15 includes a grip portion 151. The user can polish the workpiece by moving the belt sander 1 while gripping the grip portion 151 and bringing the sanding belt 27 into contact with the workpiece. The grip portion 151 is also referred to as the main grip.

[0026] The following describes the detailed configuration of Belt Thunder 1.

[0027] First, we will describe the main housing 11 and the elements located inside the main housing 11.

[0028] As shown in Figure 4, the main housing 11 is formed in an L-shape when viewed from the side. The rear portion 14 of the main housing 11 protrudes upward more than the front portion 12.

[0029] The upper end of the front half portion 12 of the main housing 11 is provided with a battery mounting portion 121 configured to removably receive a rechargeable battery 120. The controller 29 is located within the front half portion 12, below the battery mounting portion 121. Although not shown in detail, the controller 29 includes a control circuit mounted on a circuit board. The controller 29 controls the operation of the belt sander 1 (e.g., power supply to the motor 21).

[0030] Furthermore, as shown in Figures 1 to 3, a front handle 13 is connected to the front end of the front half portion 12 of the main body housing 11. The front handle 13 is generally U-shaped. Both ends of the front handle 13 are rotatably supported on the side walls of the front half portion 12. The front handle 13 includes a grip portion 131 configured to be grasped by the user. The grip portion 131 extends generally in the left-right direction. The grip portion 131 is usually used auxiliaryly together with the grip portion 151 (main grip) of the handle housing 15, and is therefore also called an auxiliary grip.

[0031] As shown in Figure 4, the upper part of the rear half portion 14 of the main housing 11 houses the motor 21. The motor 21 is positioned such that the rotation axis of the output shaft 211 of the motor 21 extends parallel to axes A1 and A2 (i.e., in the left-right direction).

[0032] The power transmission mechanism 23 is configured to rotate the sanding belt 27 by transmitting power from the motor 21 to the drive roller 25. Although detailed description and illustration are omitted, the power transmission mechanism 23 includes a first pulley, an intermediate shaft having a second pulley, an endless synchronous belt, and a reduction gear mechanism. The first pulley rotates integrally with the output shaft 211 of the motor 21. The intermediate shaft extends in the left-right direction below the motor 21. The synchronous belt is stretched between the first and second pulleys. The intermediate shaft is operably connected to the drive roller 25 via the reduction gear mechanism. The drive roller 25 and the driven roller 26 are rotatably supported by a support frame 111 (see Figure 1) attached to the lower end of the main housing 11.

[0033] The handle housing 15 and the elements located inside the handle housing 15 will be described below.

[0034] As shown in Figures 1 to 4, the handle housing 15 includes a grip portion 151, an upper connecting portion 153, and a lower connecting portion 155. The grip portion 151 is a long, cylindrical portion configured to be gripped by the user. The upper connecting portion 153 connects the upper rear end of the main housing 11 to the upper end of the grip portion 151. The lower connecting portion 155 connects the lower rear end of the main housing 11 to the lower end of the grip portion 151. The grip portion 151 extends diagonally backward from its upper end to its lower end.

[0035] As shown in Figure 5, a first switch 31 and a second switch 61 are located inside the handle housing 15. More specifically, the first switch 31 is located in the upper connecting portion 153. The second switch 61 is located in the grip portion 151. The first switch 31 and the second switch 61 are switches for starting the motor 21. The first switch 31 and the second switch 61 are momentary switches and are electrically connected to the controller 29. In this embodiment, the controller 29 is configured to supply power to the motor 21 from the battery 120 via the battery mounting portion 121, thereby driving the motor 21, while both the first switch 31 and the second switch 61 are in the ON state.

[0036] The handle housing 15 also includes a switch lever (also called a trigger) 33 and a lock-off lever 63. The switch lever 33 is a manual operating member for switching the first switch 31 on and off. The lock-off lever 63 is a manual operating member for switching the second switch 61 on and off.

[0037] The switch lever 33 is located on the upper end of the grip portion 151, on the side facing the rear end of the main body housing 11 (inside the loop). In other words, the switch lever 33 is positioned where the user's index finger rests when gripping the grip portion 151. The switch lever 33 is a rotatable lever and is supported by the handle housing 15 so as to be rotatable around an axis A3 extending in the left-right direction. The switch lever 33 is rotatable between the off position shown by the solid line in Figure 5 and the on position shown by the dashed line in Figure 5. The switch lever 33 is biased toward the off position by the biasing member 38 and is held in the off position in the initial state when no external force is applied.

[0038] The switch lever 33 comprises an elongated body portion 34. The switch lever 33 is rotatably supported at the first end portion 341 of the body portion 34. An operating projection 345 protrudes from the first end portion 341 of the body portion 34 in the longitudinal direction of the body portion 34. When the switch lever 33 is in the off position, the operating projection 345 is located within the upper connecting portion 153, spaced rearward from the actuator 315 of the first switch 31. Therefore, the first switch 31 is maintained in the off state. The second end portion 342 of the switch lever 33 protrudes outward (below the grip portion 151, inside the loop) through an opening formed in the grip portion 151, and can receive a pressing operation (pulling operation) by the user.

[0039] When the switch lever 33 is moved to the ON position in response to the user's pressing operation, the operating projection 345 presses the actuator 315 of the first switch 31 from behind, turning the first switch 31 ON. The first switch 31 remains ON while the switch lever 33 is in the ON position.

[0040] The lock-off lever 63 is located on the upper side (outside the loop) of the upper end of the grip portion 151. The lock-off lever 63 is a rotatable lever and is supported by the handle housing 15 so as to be rotatable around an axis A4 that extends in the left-right direction. The lock-off lever 63 is rotatable between the off position shown by the solid line in Figure 5 and the on position shown by the dashed line in Figure 5. The lock-off lever 63 is biased toward the off position by the biasing member 64 and is held in the off position in the initial state when no external force is applied.

[0041] The lock-off lever 63 is rotatably supported at its first end 631. When the lock-off lever 63 is in the off position, its second end 632 is located within the grip portion 151, spaced upward from the actuator 615 of the second switch 61. Therefore, the second switch 61 remains in the off state. Most of the lock-off lever 63 protrudes outward (above the grip portion 151) through an opening formed in the grip portion 151, allowing it to be pressed by the user. When the lock-off lever 63 is moved to the on position in response to the user's press, the second end 632 of the lock-off lever 63 presses the actuator 615 of the second switch 61 from above, turning the second switch 61 on. While the lock-off lever 63 is in the on position, the second switch 61 remains in the on state.

[0042] As described above, in this embodiment, the controller 29 drives the motor 21 while both the first switch 31 and the second switch 61 are ON, and stops driving the motor 21 when at least one of the first switch 31 and the second switch 61 is OFF. In other words, the controller 29 drives the motor 21 while the switch lever 33 and the lock-off lever 63 are in their respective ON positions, and stops driving the motor 21 as at least one of the switch lever 33 and the lock-off lever 63 moves to the OFF position. Therefore, the belt sander 1 has a function (hereinafter also referred to as the lock-on function) that restricts the movement of the switch lever 33 and the lock-off lever 63 from the ON position to the OFF position (prevents movement to the OFF position) in order to eliminate the need for the user to continue gripping the grip portion 151 in order to continue driving the motor 21.

[0043] Furthermore, if the switch lever 33 and the lock-off lever 63 are pressed unintentionally by the user, the sanding belt 27 may rotate in response to the motor 21's drive, potentially causing the belt sander 1 to move across the surface of the workpiece. Therefore, the belt sander 1 has a function (hereinafter also referred to as a lock-off mechanism) that restricts the movement of the switch lever 33 from the off position to the on position (prevents movement to the on position) in order to prevent the motor 21 from being driven unintentionally.

[0044] More specifically, as shown in Figure 3, the belt sander 1 includes a first lock button 4 configured to provide lock-on and lock-off functions for the switch lever 33. The first lock button 4 can also be called a lock-off / lock-on button. The belt sander 1 also includes a second lock button 7 configured to provide lock-on function for the lock-off lever 63. The second lock button 7 can also be called a lock-on button.

[0045] The configuration of the first lock button 4 and the switch lever 33 corresponding to the first lock button 4 will be described below.

[0046] The first lock button 4 is supported above the switch lever 33 by the handle housing 15 so as to be movable in the left-right direction. As shown in Figures 5 to 7, the first lock button 4 includes a main body 41, two lock-on protrusions 43, a spring retaining part 45, and two lock-off protrusions 47.

[0047] The main body portion 41 is formed in an elongated cylindrical shape overall. The two ends 410 of the main body portion 41 in the direction of its long axis have substantially the same diameter. The main body portion 41 is supported by the handle housing 15 and extends in the left-right direction. More specifically, as shown in Figure 8, openings 160 are formed in each of the left and right side walls 16 of the handle housing 15 (the upper end of the grip portion 151). In other words, the handle housing 15 has two openings 160. The two openings 160 have substantially the same shape and lie on a straight line extending in the left-right direction of the handle housing 15. More specifically, the openings 160 are through holes with a substantially circular cross-section and have a diameter slightly larger than the diameter of the ends 410 of the main body portion 41. The two ends 410 of the main body portion 41 are each inserted into the openings 160 and supported so as to be slidable in the left-right direction relative to the handle housing 15.

[0048] In the following description, when both of the two ends 410 of the main body 41 are mentioned, or when either one is mentioned without distinction, they will simply be referred to as the ends 410. Also, when one of the two ends 410 is mentioned, it will be referred to as the left end 410L, and when the right end is mentioned, it will be referred to as the right end 410R. The same method of reference will be adopted for the side wall 16 and the opening 160, as well as the pair of left and right elements mentioned below.

[0049] Each end 410 of the main body 41 constitutes an operating part that can be operated by the user's fingers. More specifically, the end surface of the main body 41 in the longitudinal direction (hereinafter referred to as the end surface 411) is the surface that receives pressure from the user's fingers. The length of the end 410 of the main body 41 is set such that when the center of the main body 41 in the longitudinal direction (left-right direction) and the center of the handle housing 15 in the left-right direction are roughly coincided, both ends 410 of the main body 41 protrude outward from the handle housing 15.

[0050] As shown in Figure 7, a recess 415 is provided in the center of the main body 41 in the left-right direction, facing the switch lever 33. The recess 415 forms a passage that crosses the main body 41 in the front-rear direction. Two lock-on protrusions 43 are positioned at the left and right ends of the recess 415 and protrude toward the switch lever 33.

[0051] As shown in Figures 5 and 6, the spring retaining portion 45 is a rectangular parallelepiped-shaped part that protrudes from the center of the main body portion 41 in the left-right direction. The spring retaining portion 45 has a recess 451 that is open upward. A biasing member 453 is held in the recess 451. The biasing member 453 is a compression coil spring.

[0052] On the other hand, as shown in Figure 9, ribs 161 protrude from the inner surfaces of the left and right side walls 16 of the handle housing 15. When the first lock button 4 is in a position where the left-right center of the main body 41 and the left-right center of the handle housing 15 are roughly coincide, each rib 161 extends into the inside of the recess 451. The tips of the two ribs 161 each abut against both ends of the biasing member 453, holding the biasing member 453 in a compressed state within the recess 451. Therefore, in the initial state where no external force is applied, the first lock button 4 is held in a position where the left-right center of the main body 41 and the left-right center of the handle housing 15 are roughly coincide (the lock-off position described later) by the biasing force of the biasing member 453.

[0053] As shown in Figures 6 and 7, the two lock-off protrusions 47 are spaced apart in the left-right direction and protrude from the spring retaining portion 45 toward the switch lever 33. The two lock-off protrusions 47 are substantially equidistant from the left-right center of the handle housing 15.

[0054] Corresponding to the lock-on projection 43 and lock-off projection 47 of the first lock button 4 as described above, the switch lever 33 is provided with one lock-on projection 35 and two lock-off projections 36.

[0055] The lock-on projection 35 of the switch lever 33 protrudes from the left-right center of the main body 34 of the switch lever 33 toward the first lock button 4. In the left-right direction, the width of the lock-on projection 35 is smaller than the distance between the lock-on projections 43 of the first lock button 4. The lock-off projection 36 is located in the longitudinal direction of the switch lever 33 between the lock-on projection 35 and the second end 342. The lock-off projection 36 protrudes from the left end and the right end of the switch lever 33 toward the first lock button 4, respectively.

[0056] The following describes the relationship between the position of the first lock button 4 and the switch lever 33 and the lock-off function and the lock-on function.

[0057] The first lock button 4 is movable left and right relative to the handle housing 15 and switch lever 33 in response to manual operation by the user. More specifically, the first lock button 4 is movable between the lock-off position shown in Figure 9, the unlock position shown in Figure 10, and the lock-on position shown in Figure 11. For the sake of simplicity, Figures 9 to 11 schematically show the positional relationship between the lock-on projection 35 and the lock-off projection 36 of the switch lever 33, the first lock button 4, and the rib 161.

[0058] The first lock button 4 can restrict the movement of the switch lever 33 from the off position to the on position when in the lock-off position. When in the unlock position, the first lock button 4 allows the switch lever 33 to move between the off position and the on position without interfering with the switch lever 33. When in the lock-on position, the first lock button 4 can hold the switch lever 33 in the on position (restricting the movement of the switch lever 33 from the off position to the on position).

[0059] More specifically, as shown in Figure 9, the position of the first lock button 4 when the lock-off projection 47 of the first lock button 4 is on the movement path of the lock-off projection 36 of the switch lever 33 defines the lock-off position of the first lock button 4. In this embodiment, the position of the first lock button 4 when the left-right center of the main body 41 and the left-right center of the handle housing 15 are approximately coincident defines the lock-off position.

[0060] When the first lock button 4 is in the lock-off position and the switch lever 33 is in the off position (shown by a solid line in Figure 5), the tip of the lock-off projection 36 of the switch lever 33 is in opposition to the tip of the lock-off projection 47 of the first lock button 4, on the path of movement of the lock-off projection 47 of the first lock button 4. Therefore, when the user presses the switch lever 33, the tip of the lock-off projection 47 of the first lock button 4 comes into contact with the tip of the lock-off projection 36 of the switch lever 33, preventing the switch lever 33 from moving to the on position. In this way, the lock-off projection 47 performs its lock-off function when the first lock button 4 is in the lock-off position.

[0061] Furthermore, when the first lock button 4 is in the lock-off position and the switch lever 33 is in the off position, the tip of the lock-on projection 35 of the switch lever 33 protrudes into the recess 415 of the first lock button 4. In other words, in the left-right direction, the lock-on projection 35 is positioned between the two lock-on projections 43 of the first lock button 4. Therefore, neither of the two lock-on projections 43 of the first lock button 4 is on the movement path of the lock-on projection 35 when the switch lever 33 moves between the off position and the on position.

[0062] The user can move the first lock button 4 from the lock-off position to the unlocked position by manually operating the first lock button 4. Specifically, when the first lock button 4 is in the lock-off position, the left end 410L and the right end 410R (operating part) of the main body 41 protrude outward from the opening 160L of the left wall 16L and the 160R of the right wall 16R of the handle housing 15, respectively (see Figure 8). The user can move the first lock button 4 from the lock-off position to the unlocked position by pushing the left end 410L or the right end 410R inward towards the handle housing 15 with their finger.

[0063] As shown in Figure 10, the position of the first lock button 4 when the lock-off projection 47 of the first lock button 4 is not on the movement path of the lock-off projection 36 of the switch lever 33, and when neither of the two lock-on projections 43 of the first lock button 4 is on the movement path of the lock-on projections 35 of the switch lever 33, defines the unlocked position. The left-right distance between the lock-on projections 43 of the first lock button 4 and the left-right width of the lock-on projections 35 of the switch lever 33 are set so that the lock-on projections 35 can move freely relative to each other in the left-right direction within the recess 451 when the first lock button 4 is moved between the lock-off position and the unlocked position.

[0064] Although detailed illustrations are omitted here, in this embodiment, the first lock button 4 has unlock positions set to the right and left of the lock-off position. In other words, the user can move the first lock button 4 from the lock-off position to the unlock position by pressing either the left end 410L or the right end 410R.

[0065] The user can manually operate the first lock button 4 to move it from the unlocked position to the locked-on position. Specifically, with the first lock button 4 in the unlocked position, the user moves the switch lever 33 to the ON position, and then pushes the first lock button 4 further inward into the handle housing 15. However, if the user attempts to push the first lock button 4 further from the unlocked position with the switch lever 33 in the OFF position, the lock-on projection 35 of the switch lever 33 will come into contact with one of the two lock-on projections 43 of the first lock button 4, preventing the first lock button 4 from moving.

[0066] As shown in Figure 11, in this embodiment, the position of the first lock button 4 when one of the two lock-on protrusions 43 of the first lock button 4 is on the movement path of the lock-on protrusion 35 of the switch lever 33 defines the lock-on position. In other words, the first lock button 4 has lock-on positions set to the right and left of the lock-off position, similar to the unlock position.

[0067] When the first lock button 4 is in the lock-on position, if the user releases pressure on the switch lever 33, which is in the ON position, the switch lever 33 moves toward the OFF position due to the biasing force of the biasing member 38. The lock-on projection 43 of the first lock button 4 contacts the lock-on projection 35 of the switch lever 33 before the switch lever 33 reaches the OFF position, preventing the switch lever 33 from moving toward the OFF position. In this way, the lock-on projection 43 performs its lock-on function when the first lock button 4 is in the lock-on position. Therefore, even if the user releases their hand from the switch lever 33, the first switch 31 remains in the ON state.

[0068] Furthermore, when the first lock button 4 is in the lock-on position and the switch lever 33 is in the ON position, the lock-off projection 47 of the first lock button 4 is not on the movement path of the lock-off projection 36 of the switch lever 33.

[0069] As described above, the first lock button 4 is biased toward the lock-off position by a biasing member 453 held by the spring retaining part 45. When the first lock button 4 is in the lock-on position, the biasing member 453 is pressed against one of the two ribs 161 and further compressed. Therefore, when the user further presses the switch lever 33, which is held in the ON position by the first lock button 4, and separates the lock-on projection 35 of the switch lever 33 from the lock-on projection 43 of the first lock button 4, the first lock button 4 returns to the lock-off position due to the restoring force of the biasing member 453.

[0070] The configuration of the second lock button 7 and the lock-off lever 63 corresponding to the second lock button 7 will be described below.

[0071] The second lock button 7 is supported so as to be movable in the left-right direction on the grip portion 151 of the handle housing 15. More specifically, as shown in Figures 3 and 4, the second lock button 7 is slidably inserted in the left-right direction through an opening (through hole) formed in the left-side wall portion 16L. The second lock button 7 includes a manually operable operating portion 71 located outside the grip portion 151 and an engaging portion 75 located inside the grip portion 151.

[0072] Corresponding to the engaging portion 75 of the second lock button 7, an opening 633 is provided in the left wall of the lock-off lever 63. The opening 633 has a size and shape that allows the engaging portion 75 to pass through. Although detailed illustrations are omitted, the second lock button 7 is biased outward (to the left) of the grip portion 151 by a biasing member and held in its initial position. When the second lock button 7 is in its initial position, the engaging portion 75 is to the left of the lock-off lever 63.

[0073] When the lock-off lever 63 is in the off position, the opening 633 and the engaging portion 75 are offset from each other. Therefore, the user cannot push the second lock button 7 to the right (inward towards the grip portion 151) from its initial position. On the other hand, when the lock-off lever 63 is in the on position, the opening 633 and the engaging portion 75 overlap. Therefore, the user can move the second lock button 7 to the lock-on position by pushing it to the right (inward towards the grip portion 151).

[0074] When the second lock button 7 is in the lock-on position, the engaging portion 75 is inserted into the lock-off lever 63 through the opening 633. When the user releases pressure on the lock-off lever 63 in this state, the engaging portion 75 engages with the surrounding wall of the opening 633, preventing the lock-off lever 63 from moving to the off position. In this way, the engaging portion 75 performs the lock-on function. Therefore, even when the user releases their hand from the lock-off lever 63, the second switch 61 remains in the ON state.

[0075] Incidentally, as described above, in this embodiment, the first lock button 4 is initially held in the lock-off position by the biasing force of the biasing member 453, and moves to the lock-on position via the unlock position in response to the user's pressing operation. Since the first lock button 4 is only supported so as to be slidable in the left-right direction, it is difficult for the user to recognize whether the first lock button 4 is in the unlock position or the lock-on position.

[0076] As shown in Figures 1 to 3 and Figure 8, the belt sander 1 of this embodiment is equipped with a first contact portion 51 and a second contact portion 52 that facilitate the user's tactile recognition of the state of the first lock button 4. The belt sander 1 is also equipped with a recess 55 that facilitates the operation of the first lock button 4. The first contact portion 51, the second contact portion 52, and the recess 55 are each provided adjacent to the opening 160 that exposes the first lock button 4 to the outside of the handle housing 15. Here, "adjacent" includes not only arrangements that are in contact with each other, but also arrangements that are in the vicinity of each other. As described above, the handle housing 15 has two openings 160L and 160R formed in the left wall portion 16L and the right wall portion 16R, respectively. Therefore, the first contact portion 51, the second contact portion 52, and the recess 55 are provided corresponding to the openings 160L and 160R, respectively.

[0077] The first contact portion 51 is provided so that the user can touch it with their finger. In this embodiment, the first contact portion 51 is configured as a projection that protrudes from the outer surface 150 of the handle housing 15 (side wall portion 16) along a part of the edge of the opening 160. More specifically, the first contact portion 51 is arranged in an arc shape along the edge of the opening 160 so as to surround at least the front half of the opening 160. Furthermore, the first contact portion 51 is integrally molded with the handle housing 15. In other words, the first contact portion 51 is composed of a part of the handle housing 15.

[0078] The second contact portion 52 is also provided so that the user can touch it with their finger. In this embodiment, the portion (region) of the outer surface 150 of the handle housing 15 adjacent to the opening 160 and the first contact portion 51 functions as the second contact portion 52.

[0079] At least a portion of the first contact portion 51 and at least a portion of the second contact portion 52 are positioned so that the user can simultaneously contact them with one finger (for example, the thumb or index finger) from outside the handle housing 15. As described above, in this embodiment, the user typically presses (pushes) the switch lever 33 with their index finger while gripping the grip portion 151. Therefore, the user can operate the first lock button 4 with their thumb, or with the fingers of a hand other than the one gripping the grip portion 151. Thus, considering the size of a typical user's fingers, the shortest distance W between the first contact portion 51 and the second contact portion 52 is preferably, for example, 15 mm or more and 30 mm or less, and more preferably 20 mm or more and 25 mm or less.

[0080] The recess 55 is configured to allow the user to insert a portion of their finger. In this embodiment, the recess 55 is formed on the outer surface 150 of the handle housing 15 in the portion (region) that contacts the opening 160. More specifically, the recess 55 extends rearward from the edge of the opening 160 that is not surrounded by the first contact portion 51 (the edge of the rear half of the opening 160). In other words, a portion of the first contact portion 51 and the recess 55 are located opposite each other across the opening 160. Therefore, when viewing the handle housing 15 from the left or right side, the first contact portion 51 (projection), the end portion 410 of the first lock button 4, and the recess 55 are on a straight line extending in the front-rear direction. Furthermore, the recess 55 is defined by a gently curving surface that conforms to the shape of a finger. In addition, the recess 55 is formed to deepen towards the edge of the opening 160 (from the rear to the front of the recess 55).

[0081] The functions of the first contact portion 51, the second contact portion 52, and the recess 55 will be explained below with reference to Figure 12. In Figure 12, the first lock button 4 in the lock-off position, unlock position, and lock-on position are shown by a solid line, a dashed line, and a dotted line, respectively.

[0082] As shown in Figure 12, in this embodiment, the length of the first lock button 4 is set such that when the first lock button 4 is in the lock-off position (the position shown by the solid line), each end 410 (more specifically, at least the entire end face 411) protrudes outward from a hypothetical plane P that is in contact with at least one point of the tip of the first contact portion 51 and at least one point of the second contact portion 52. Therefore, the user can easily recognize that the first lock button 4 is in the lock-off position by visually inspecting the end 410 or by touching at least one of the first contact portion 51 and the second contact portion 52 and the end 410 with their finger.

[0083] Furthermore, when the first lock button 4 is in the lock-off position, the amount of protrusion of the end 410 from the tip of the first contact portion 51 (the distance between the tip of the first contact portion 51 and the end face 411 in the direction of movement of the first lock button 4 (i.e., left-right direction): T) is preferably set so that the user can easily recognize that the first lock button 4 is in the lock-off position through sight and touch. The amount of protrusion T can be set, for example, within the range of 2.5 mm to 3.0 mm.

[0084] When the user wants to move the first lock button 4 from the lock-off position, the user can press the end portion 410 (end face 411) of the first lock button 4 with their finger. When the first lock button 4 is pushed inward to a certain extent within the handle housing 15, the user's finger comes into contact with the first contact portion 51 and the second contact portion 52. In this embodiment, the first lock button 4, the first contact portion 51 and the second contact portion 52 are configured such that the first lock button 4 is positioned in the unlocked position (indicated by the dashed line) as the first lock button 4 is pushed in to a position where the user's finger comes into contact with the first contact portion 51 and the second contact portion 52. The plane P described above can be said to roughly correspond to the surface of the user's finger when the user places their finger on the first contact portion 51 and the second contact portion 52. Therefore, the unlock position of the first lock button 4 is defined as the position where the end face 411 of the pressed end 410 is located near the plane P (more specifically, the position where at least a portion of the end face 411 is located slightly inward from the plane P).

[0085] In this way, the first contact portion 51 and the second contact portion 52 allow the user to easily recognize that the first lock button 4 has been moved to the unlocked position (i.e., that the lock-off state of the switch lever 33 has been released). It is preferable that the amount of protrusion of the first contact portion 51 from the outer surface 150 of the handle housing 15 (the distance S between the tip of the first contact portion 51 and the outer surface 150 in the direction of movement of the first lock button 4 (i.e., left and right direction)) be set so that the user's finger can easily touch both the first contact portion 51 protruding from the outer surface 150 and the second contact portion 52, which is part of the outer surface 150, at the same time. The amount of protrusion S can be set, for example, within the range of 0.5 mm to 1.5 mm.

[0086] Furthermore, the lock-on position of the first lock button 4 (indicated by the dashed line) is defined as a position where the end face 411 of the pressed end 410 is completely positioned inward from the plane P. In this embodiment, when the first lock button 4 is in the lock-on position, the entire end face 411 is completely separated inward from the plane P. Therefore, the user basically needs to insert their fingertip into the opening 160 to move the first lock button 4 to the lock-on position. In other words, it is difficult to move the first lock button 4 to the lock-on position when the user's finger is in contact with the first contact portion 51 and the second contact portion. Thus, the possibility of the user unconsciously moving the first lock button 4 to the lock-on position can be reduced. In this way, the first contact portion 51 and the second contact portion 52, by contacting the user's finger, restrict the user from moving the first lock button 4 to the lock-on position and make the user aware that they need to move their finger and press the end face 411 in order to move it to the lock-on position.

[0087] In this embodiment, a recess 55 is provided adjacent to the opening 160. Therefore, the user can push the first lock button 4 from the unlocked position to the lock-on position by pressing the end face 411 of the end 410 with part of their finger placed inside the recess 55. In this way, the recess 55 makes it easier for the user to move the first lock button 4 to the lock-on position by accommodating the user's finger. It is preferable that the maximum depth of the recess 55 (the maximum distance between the outer surface 150 and the bottom of the recess 55 in the direction of movement of the first lock button 4 (i.e., left-right direction)) be set so that the user can easily touch the end face 411 of the first lock button 4 in the lock-on position with their finger placed inside the recess 55. The depth can be set, for example, within the range of 3.5 mm to 4.0 mm.

[0088] As described above, the first contact portion 51 and the second contact portion 52, which are provided adjacent to the opening 160 that exposes the end portion 410 of the first lock button 4 to the outside, enable the user to easily recognize the operating state of the first lock button 4 through touch.

[0089] The correspondence between each component (feature) of the above embodiments and each component (feature) of the present disclosure or invention is shown below. However, each component of the embodiments is merely an example and does not limit each component of the present disclosure or invention.

[0090] Belt sander 1 is an example of an "electric work machine". Motor 21 is an example of a "motor". First switch 31 is an example of a "switch". Switch lever 33 is an example of a "switch operating member". First lock button 4 is an example of a "locking member". End portion 410 of the main body 41 is an example of an "operating part". Housing 10 (specifically, handle housing 15) is an example of a "housing". Opening 160 is an example of an "opening". First contact portion 51 is an example of a "first contact portion". Second contact portion 52 is an example of a "second contact portion". Outer surface 150 is an example of an "outer surface of the housing". Recess 55 is an example of a "recess". Grip portion 151 is an example of a "grip portion".

[0091] The above embodiments are merely illustrative, and the electric work machine relating to this disclosure is not limited to the illustrated belt sander 1. For example, modifications as illustrated below can be made. Furthermore, at least one of these modifications may be adopted in combination with the belt sander 1 illustrated in the embodiments and at least one of the features described in each claim.

[0092] The electric work implements relating to this disclosure refer to any machine capable of performing various tasks (e.g., processing workpieces, farming, gardening, etc.) using the power of an electric motor. This disclosure may be applied to any electric work implement comprising a motor start switch, a switch operating member for turning the switch on and off, and a locking member capable of selectively holding the switch operating member in the on and off positions.

[0093] The configuration, arrangement, support manner, and / or operating manner of the switch operating member and locking member may differ from those of the switch lever 33 and first lock button 4 exemplified in the above embodiment. Furthermore, a second switch and second switch operating member, such as the second switch 61 and lock-off lever 63, are not necessarily required.

[0094] For example, the shape, number, and / or arrangement of the lock-off and lock-on protrusions of the switch operating member and the locking member can be selected as appropriate. The locking member may be supported within the housing by a support member separate from the housing, such that the operating part is exposed to the outside through the opening of the housing. In such modifications, the first and second contact portions may be provided on the support member rather than on the housing.

[0095] Furthermore, in the above embodiment, for a single lock-off position, two unlock positions and two lock-on positions are set. Therefore, the first lock button 4 can move to the unlock position and the lock-on position regardless of whether it is moved from the lock-off position in two opposite directions (left and right). However, the locking member may have only one lock-off position, one unlock position, and one lock-on position. In other words, the locking member may be able to move in only one predetermined direction from the lock-off position through the unlock position to the lock-on position. Also, the locking member is not limited to being able to move in a straight line, but may be able to rotate.

[0096] The configurations of the first and second contact portions according to this disclosure may differ from the exemplified first contact portion 51 (protrusion) and second contact portion 52 (part of the outer surface 150 of the handle housing 15). For example, the first and second contact portions may each be separate protrusions that protrude from the outer surface of the housing (e.g., the housing including the grip portion). Alternatively, the first and second contact portions may be spaced-apart portions of a single protrusion. The first and second contact portions may both be parts of the outer surface of the housing. Furthermore, while a recess is preferable to facilitate the pressing operation from the unlocked position to the locked position, the recess may be omitted.

[0097] Furthermore, the first contact portion, the second contact portion, and the recess only need to be adjacent to the opening that exposes the operating portion of the locking member to the outside, and their arrangement can be set as appropriate. Figures 13 to 15 show specific variations in the arrangement of the first contact portion 51, the second contact portion 52, and the recess 55 as the second to fourth embodiments, respectively. These variations can also be used to obtain the same effects as the first contact portion 51, the second contact portion 52, and the recess 55 of the above embodiment.

[0098] In the second embodiment shown in Figure 13, the first contact portion 51A is positioned on the opposite side of the opening 160 from the switch lever 33 in the extending direction of the grip portion 151. The first contact portion 51A is an arc-shaped projection provided along a part of the edge of the opening 160, similar to the first contact portion 51 in the above embodiment (see Figure 3). The first contact portion 51A and the recess 55A are opposite each other with the opening 160 in between. The second contact portion 52A is a part of the outer surface 150 adjacent to the first contact portion 51 and the recess 55A.

[0099] In the third embodiment shown in Figure 14, the first contact portion 51B is positioned to surround the upper half of the opening 160. The first contact portion 51B is also an arc-shaped projection provided along a part of the edge of the opening 160. The first contact portion 51B and the recess 55B face each other across the opening 160. The second contact portion 52B is a part of the outer surface 150 adjacent to the first contact portion 51B and the recess 55B.

[0100] In the fourth embodiment shown in Figure 15, the first contact portion 51C and the recess 55C face each other across the opening 160 in a direction perpendicular to the extending direction of the grip portion 151. The first contact portion 51C is also an arc-shaped projection provided along a part of the edge of the opening 160. The second contact portion 52C is a part of the outer surface 150 adjacent to the first contact portion 51C and the recess 55C.

[0101] In view of the spirit of the present invention and the embodiments described above, the following embodiments can be constructed. At least one of the following embodiments may be adopted in combination with the features of the embodiments and their modifications, or at least one of the features described in each claim. [Aspect 1] The first restricting portion and the second restricting portion are arranged so that the user's fingers can make contact with them simultaneously. [Aspect 2] The locking member is configured to reach the lock-on position when the operating part is pressed while the user's finger is inserted inside the opening. [Aspect 3] The system further comprises a biasing member configured to bias the locking member toward the lock-off position, The locking member is held in the lock-off position in its initial state. [Aspect 4] The system further comprises a biasing member configured to bias the switch operating member toward the off position, The switch operating member is held in the off position in the initial state. [Aspect 5] The switch operating member is movable in the first direction, The locking member is movable in a second direction intersecting the first direction. [Aspect 6] The switch operating member is a lever that can rotate around an axis extending in the second direction, The locking member is movable linearly in the second direction. [Aspect 7] The aforementioned electric work machine is a belt sander, A drive roller is operably connected to the output shaft of the motor and configured to rotate around a first axis in response to the drive of the motor, A driven roller rotatably supported around a second axis parallel to the first axis, The system further comprises an endless sanding belt stretched between the drive roller and the driven roller. [Explanation of Symbols]

[0102] 1: Belt sander, 10: Housing, 11: Main housing, 111: Support frame, 113: Plate, 12: Front part, 120: Battery, 121: Battery mounting part, 13: Front handle, 131: Grip part, 14: Rear part, 15: Handle housing, 150: Outer surface, 151: Grip part, 153: Upper connecting part, 155: Lower connecting part, 16, 16L, 16R: Side wall part, 160, 160L, 160R: Opening, 161: Rib, 21: Motor, 23: Power transmission mechanism, 25: Drive roller, 26: Driven roller, 27: Sanding belt, 29: Controller, 31: First switch, 33: Switch lever, 34: Main body part, 35: Lock-on projection, 36: Lock-off projection, 38: Biasing member, 4 :First lock button, 41:Main body, 43:Lock-on projection, 45:Spring retaining part, 47:Lock-off projection, 51, 51A, 51B, 51C:First contact part, 52, 52A, 52B, 52C:Second contact part, 55, 55A, 55B, 55C:Recess, 61:Second switch, 63:Lock-off lever, 64:Biasing member, 7:Second lock button, 71:Operating part, 75: Engaging part, 211: Output shaft, 315: Actuator, 341: First end, 342: Second end, 345: Actuating projection, 410, 410L, 410R: End, 411: End face, 415: Recess, 451: Recess, 453: Biasing member, 615: Actuator, 631: First end, 632: Second end, 633: Opening, A1: Shaft, A2: Shaft, P: Plane,

Claims

1. Motor and, The motor start switch, A switch operating member that can move between an off position, where the switch is in an off state, and an on position, where the switch is in an on state, in response to manual operation by the user, A locking member having an operating part, wherein, in response to a user's pressing operation on the operating part, the locking member is supported so as to be movable from a lock-off position that restricts the movement of the switch operating member from the off position to the on position, via an unlocked position that allows movement of the switch operating member between the off position and the on position, to a lock-on position that restricts the movement of the switch operating member from the on position to the off position, A housing having an opening that exposes the operating portion of the locking member so that it can be pressed and operated from the outside, The device is provided with a first contact portion and a second contact portion adjacent to the opening so that the user can touch it with their fingers. When the locking member is in the lock-off position, the operating portion protrudes outward from the virtual plane that contacts the first contact portion and the second contact portion. When the locking member is in the lock-on position, the operating part is located inward from the plane. The unlock position is set between the lock-off position and the lock-on position. The electric work machine is characterized in that the first contact portion and the second contact portion are configured to restrict the pressing operation that moves the locking member from the unlocked position to the locked-on position by contacting the user's finger.

2. An electric work machine according to claim 1, The electric work machine is characterized in that the locking member is configured to be positioned in the unlocked position in accordance with the fact that at least a part of the operating portion is positioned inward from the plane.

3. An electric work machine according to claim 1 or 2, An electric work machine characterized in that at least one of the first contact portion and the second contact portion is a protruding portion that protrudes from the outer surface of the housing.

4. An electric work machine according to claim 3, The first contact portion is the protruding portion, The electric work machine is characterized in that the second contact portion is a part of the outer surface of the housing.

5. An electric work machine according to claim 4, The electric work machine is characterized in that the first contact portion is formed integrally with the housing.

6. An electric work machine according to claim 5, The electric work machine is characterized in that the locking member is supported by the housing.

7. An electric work machine according to claim 1 or 2, An electric work machine characterized by further comprising a recess provided adjacent to the opening, on which the user can position a part of their finger.

8. An electric work machine according to claim 7, The aforementioned recess is recessed from the outer surface of the housing and is characterized by being defined by a curved surface.

9. An electric work machine according to claim 8, An electric work machine characterized in that at least a portion of the first contact portion and the recess face each other across the opening in a direction perpendicular to the direction of movement of the locking member.

10. An electric work machine according to claim 1 or 2, The housing includes a grip portion configured to be held by the user, The electric work machine is characterized in that the switch operating member and the locking member are positioned so that the user can operate them with their index finger and thumb, respectively, while holding the grip portion.

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