Thermal overload relay

A thermal overload relay comprising:

• a main bimetal displaced by bending deformation upon detection of an overload current;
• a shifter cooperating with operation of the main bimetal;
• a release lever working according to a displacement of the shifter that displaces following a displacement of the main bimetal;
• a contact reversing mechanism for changing-over contacts by reversing action caused by rotation of the release lever;
• a case for retaining the main bimetal, release lever, and contact reversing mechanism;
• a manipulation structure held in the case for manipulating the release lever and the contact reversing mechanism, the manipulation structure including a reset bar for returning the contact reversing mechanism to an initial state, the reset bar partially protruding out of the case and being arranged to change-over between a manual reset state in which the reset bar can be pushed-in and an automatic reset state in which the reset bar is pushed-in and turned from the manual reset state and held in that state;
• and
• a cover slidably attached on the case to be able to cover the manipulation structure, the cover including an elongated reset bar passing window to pass a head of the reset bar with a longitudinal direction being in a sliding direction of the cover, and a locking projection formed at one longitudinal end on a periphery of the reset bar passing window,
• wherein the reset bar is positioned at one longitudinal end of the reset bar passing window by sliding the cover towards a direction to cover the manipulation structure in the manual reset state and the automatic reset state;
• and
• the reset bar includes a bar locking slot on an outer circumferential surface thereof, and is held in a pushed-in state by coupling the bar locking slot and the locking projection formed at one end of the reset bar passing window in the automatic reset state.