Push button switch structure

A push button switch structure, comprising:

• casing means for encasing switch components;
• supporting means disposed within the casing means, said supporting means for supporting electronic components thereupon;
• switching means disposed on said supporting means, said switching means for switching between ON state and OFF state;
• and
• actuating means disposed in an opening of the casing means, said actuating means for actuating the switching means, said actuating means comprising a pushing portion for engagement by a user, a pushing projection disposed on an inner surface of the pushing portion and projecting toward an inner portion of the casing means, wherein the pushing projection is for coming into and out of contact with the switching means, and an annular wall portion surrounding a periphery of the pushing projection,
• wherein the pushing portion, the pushing projection, and the annular wall portion are integrally formed of elastic material, and
• wherein the annular wall portion and the pushing projection are disposed in an interior of the casing means such that the pushing portion projects outwardly from the opening portion of the casing means and a distal end portion of the pushing projection is directed toward the switching means,
• said push button switch structure further comprising
• guiding means for restricting movement of the pushing projection, said guiding means disposed inside the annular wall portion of the actuating means,
• wherein the guiding means comprises a sleeve portion extending along an inner side of the annular wall portion, and a ceiling portion configured to cover an opening of the sleeve portion, extending along an inner side of the pushing portion with a gap therebetween, and extending over the switching means, and
• wherein the guiding means is arranged outside the switching means in a surrounding manner, and comprises a lower end portion thereof mounted on the supporting means, and
• wherein the pushing projection is configured to be moved into and out of an opening in the ceiling portion.

A method of assembling a switch, comprising:

• providing a switch casing, and a printed circuit board disposed within said casing, wherein a switching element is disposed on the printed circuit board;
• providing a push button which is configured to be disposed in an opening of the switch casing, with the push button including a pushing portion configured to be pushed by a user, and a pushing projection on an inner surface of the pushing portion, wherein the pushing projection is configured, when the push button is disposed in the switch casing, to project toward an inner portion of the switch casing, wherein the pushing projection is configured to come into and out of contact with the switch element, wherein an annular wall portion surrounds a periphery of the pushing projection, and wherein the pushing portion, the pushing projection, and the annular wall portion are integrally configured of elastic material;
• providing a guide member attached to said switching casing;
• and
• placing the push button in the opening of the switch casing, such that the annular wall portion and the pushing projection are disposed in an interior of the switch casing such that the pushing portion projects outwardly from the opening of the switch casing, and a distal end portion of the pushing projection is directed toward the switch element,
• wherein the guide member restricts movement of the pushing projection during switch actuation,
• wherein the guide member comprises a sleeve portion extending along an inner side of the annular wall portion, and a ceiling portion configured to cover an opening of the sleeve portion, extending along an inner side of the pushing portion with a gap therebetween, and extending over the switching element,
• wherein the guide member is arranged outside the switching element in a surrounding manner, and comprises a lower end portion thereof mounted on the printed circuit board, and
• wherein the pushing projection is configured to be moved into and out of an opening in the ceiling portion.