Push switch

1. A push switch comprising:

a pressing member including a pressing portion configured to be pressed, and including an elastically deformable peripheral wall portion having a lower end portion and extending downward and outward from an outer periphery of the pressing portion,

a movable contact having a dome shape and disposed below the pressing member;

an interposed member disposed between the pressing member and the movable contact, and configured to press the movable contact by receiving and being pressed by the lower end portion of the peripheral wall portion of the pressing member;

a first fixed contact provided in contact with the movable contact; and

a second fixed contact configured to be contacted with and separated from the movable contact,

wherein the lower end portion of the peripheral wall portion of the pressing member presses the interposed member while the peripheral wall portion is subjected to elastic deformation in response to the pressing portion being pressed, and

wherein the interposed member is configured to move toward the movable contact, thereby pressing the movable contact upon receiving a pressing force from the pressing member.

2. The push switch according to claim 1 , wherein the pressing member has load characteristics in which the elastic deformation of the peripheral wall portion causes an operation load to increase such that an amount of increase in an operation load per unit operation amount gradually decreases.

3. The push switch according to claim 1 , wherein the pressing member further includes an elastically deformable support portion configured to support the peripheral wall portion such that the peripheral wall portion is vertically movable, and

wherein the lower end portion of the peripheral wall portion is spaced apart from the interposed member while the pressing portion is in a non-pressed state.

4. The push switch according to claim 1 , wherein the interposed member includes

a contact portion having a flat plate shape, and configured to receive the lower end portion of the peripheral wall portion, and

a first protruding portion that protrudes downward from a center of the contact portion.

5. The push switch according to claim 4 , wherein the pressing member further includes an elastically deformable second protruding portion, the second protruding portion having a lower end portion, and being disposed within a space surrounded by the peripheral wall portion to protrude downward from the pressing portion, and

wherein the elastic deformation of the peripheral wall portion causes the second protruding portion to be moved downward, and the lower end portion of the second protruding portion contacts the interposed member before the peripheral wall portion is inverted.

6. The push switch according to claim 5 , wherein the movable contact is inverted and contacts the second fixed contact, upon the interposed member being pressed by both the lower end portion of the peripheral wall portion and the lower end portion of the second protruding portion.

7. The push switch according to claim 1 , wherein the movable contact is made from a dome-shaped metal plate that has a spring characteristic.