Thermal-type over load relay
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorYuji Sako
Life of this patent
Estimating the term…
Abstract
A thermal-type over load relay having an improved contact operating mechanism whereby testing of the operation of the relay is made easy, malfunctions due to mechanical shock or the like are substantially eliminated, and the overall size of the relay is reduced. A thermal element is provided for opening normally closed contacts of the relay in response to heat produced by a heater through which a main circuit current flows. An operating rod is provided for closing the normally open contacts in response to the operation of a normally closed contact mechanism when the normally closed contacts are opened by the operation of the thermal element. The operating rod may be operated from the exterior of the housing of the relay for testing purposes.
Claims11
A thermal-type over load relay comprising:
- a normally closed contact mechanism having normally closed contacts;
- a normally open contact mechanism having normally open contacts;
- a thermal element atuated by heat produced by a heater through which a main circuit current flows for opening said normally closed contacts;
- a movably mounted operating rod for opening said normally open contacts of said normally open contact mechanism and for closing normally open contacts in response to operation of said normally closed contact mechanism when said normally closed contacts are opened by actuation of said thermal element;
- and
- a housing enclosing said operating rod, said thermal element, said normally closed contact mechanism, and said normally open contact mechanism;
- said operating rod having an operating portion projecting externally of said housing for closing said normally open contacts by manually moving said operating rod externally of said housing.
A thermal-type over load relay comprising:
- a normally closed contact mechanism having normally closed contacts;
- a normally open contact mechanism having normally open contacts;
- a thermal element actuated by heat from a heater through which a main circuit current flows for opening said normally closed contacts;
- an operating rod movably mounted to open said normally open contacts of said normally open contact mechanism and for closing said normally open contacts in response to operation of said normally closed contact mechanism when said normally closed contacts are opened by actuation of said thermal element;
- a housing enclosing said operating rod, said thermal element, said normally closed contact mechanism, and said normally open contact mechanism;
- said operating rod having an operating portion projecting externally of said housing for closing said normally open contacts by manually moving said operating rod externally of said housing;
- and
- a reset rod supported on said housing in such a manner as to be movable in a direction substantially perpendicular to a direction of movement of said operating rod for returning said operating rod to open said normally open contacts.
Dependencies are inferred from the claim text.