A circuit breaker includes a main body case, an operating handle having a base portion and a knob portion protruding outwardly through a handle window frame opened in a cover of the main body case; a first shutter arranged between the base portion of the operating handle and the handle window frame, and disposed on the base portion, the first shutter being formed with a loose-fit hole to loosely fit the knob portion therethrough; and a second shutter disposed on the first shutter to move along with the knob portion. At ON and OFF positions of the operating handle, the first shutter extends beyond a front/rear edge of the handle window frame in a front-back direction to close the handle window frame, and the second shutter extends beyond a front/rear edge of the loose-fit hole in the front-back direction to close the loose-fit hole.

An operating device includes a knob, which is formed into a rod form, and a resilient body, which is formed into a ring form. Position limiting parts, which limit a position of the resilient body, include at least one primary rib, which is placed on one side of the resilient body in a longitudinal direction of the knob, and at least one secondary rib, which is placed on another side of the resilient body in the longitudinal direction of the knob. The at least one primary rib and the at least one secondary rib radially outwardly project from the outer peripheral portion of the knob within an extent that does not extend beyond the resilient body.

A double seesaw switch has two seesaw switches arranged side-by-side inside a case. Each of the two seesaw switches has a central terminal arranged on a bottom surface inside the case, a pair of fixed contacts separately arranged, a moving contact supported pivotably with respect to the central terminal and has a contact portion for contacting one of the fixed contacts, an operation body supported rotatably with respect to the case, and pivots the moving contact by moving on the moving contact in correspondence with a rotation movement of the operation body, and a biasing part biasing the operation body towards a neutral position. The biasing part is a leaf spring piece formed in a U shape from a portion of a ceiling surface of the case, and to press against the operation body in a power storing state of a leading end portion compressed.

A power tool (1) includes an electric motor (2) as a drive source and a start switch (20; 61) that starts the electric motor (2) and is lockable in an ON position in a lock-ON state. An electromagnetic actuator (30; 40; 50; 60) pushes out or pulls in an actuation pin (30a; 40a; 50a; 60a) with respect to a body of the electromagnetic actuator (30; 40; 50; 60) in response to cutting off of a supply of electrical current to the power tool (1). The pushed-out or pulled-in actuation pin, directly or indirectly, disengages the start switch (20; 61) from the lock-ON state and/or prevents the start switch (20; 61) from being shifted into the lock-ON state.

A power tool (1) includes an electric motor (2) as a drive source and a start switch (20; 61) that starts the electric motor (2) and is lockable in an ON position in a lock-ON state. An electromagnetic actuator (30; 40; 50; 60) pushes out or pulls in an actuation pin (30a; 40a; 50a; 60a) with respect to a body of the electromagnetic actuator (30; 40; 50; 60) in response to cutting off of a supply of electrical current to the power tool (1). The pushed-out or pulled-in actuation pin, directly or indirectly, disengages the start switch (20; 61) from the lock-ON state and/or prevents the start switch (20; 61) from being shifted into the lock-ON state.

A control device, includes a switch (2) with a rotary control rod (20) having a diametrical slot (21) which extends in a plane of reference (P), a molded plastic knob (3) which includes a housing receiving the control rod, the housing including two flexible fingers (31, 32) which are diametrically opposed and provided so as to be resilient radially inward, and two fixed fingers (33, 34) which are diametrically opposed and are connected together via a connecting wall (35) which extends along the plane (P), the connecting wall (35) being received in the diametric slot without any play in order to immobilize the knob in relation to the control rod in a direction (Y) perpendicular to the plane (P), the two flexible fingers holding the knob along the axis (A) by friction or by mechanical or spring-assisted blocking.