Depression responsive switch unit

A depression responsive switch unit in which a switch is turned on in response to a depression operation comprising

• a case including a surface place in which an opening is formed;
• a reinforcing plate disposed opposite to a rear plate of the case and disposed within the case so as to be reciprocable relative to the rear plate;
• a second step switch interposed between the reinforcing plate and the rear plate and operated on by a movement of the reinforcing plate toward the rear plate;
• a plurality of first step switches disposed on the reinforcing plate on the side located toward the surface plate;
• a key operation base disposed on the case so as to block the opening in the surface plate and formed with depression openings corresponding to the location of each first step switch;
• and a knob disposed between the reinforcing plate and the key operation base;
• the knob including an elastic sheet which is formed of a thermoplastic elastomer or a silicone rubber and having a marginal portion which is held sandwiched between the key operation base and the reinforcing plate to be secured, depressing pieces formed on the elastic sheet so as to correspond to each first step switch, each depressing piece being disposed in a depression opening formed in the key operation base, and a small projection projecting from elastic sheet for each depressing piece to be located close to or in contact with the first step switch.

A depression responsive switch unit in which a switch is turned on in response to a depression operation, comprising

• a case including a surface plate in which an opening is formed;
• a reinforcing plate disposed opposite to a rear plate of the case and disposed within the case so as to be reciprocable with respect to the rear plate;
• a second step switch interposed between the reinforcing plate and the rear plate and operated on by a movement of the reinforcing plate toward the rear plate;
• a plurality of first step switches disposed on the reinforcing plate on the side located toward the surface plate;
• a key operation base disposed on the case in a manner to block the opening in the surface plate and having depression openings formed therein in a manner corresponding to the location of each first step switch;
• and a knob disposed on the key operation base on the opposite side from the reinforcing plate;
• the knob including an elastic sheet which is formed of a thermoplastic elastomer or silicone rubber and having a marginal portion which is secured by being held sandwiched between the key operation base and the reinforcing plate, depressing pieces formed on the elastic sheet in a manner corresponding to each first step switch and each having a depressed surface on the front side of the elastic sheet and each disposed in the depression opening, and a small projection projecting from each depressing piece in the opposite direction from the depressed surface to be located close to or in contact with the first step switch.

A depression responsive switch unit in which a switch is turned on in response to the depression of a knob, comprising

• a case including a surface plate in which an opening is formed, a rear plate opposing to said surface plate and a side wall between said surface plate and said rear plate;
• a knob having a top plate portion disposed in the opening and a projection member disposed on the top plate portion to extend perpendicularly from the top plate portion toward the rear plate, said projection member having a projection end and an annular end surface portion surrounding said projection end;
• a resilient member of a resilient material having an annular case connector portion secured to said side wall of the case, an annular knob connector portion secured to said annular end surface portion, and a body portion which integrally connects the knob connector portion to the case connector portion, wherein said resilient member is adapted to allow the knob to be readily displaceable in the direction of a depression which is perpendicular to the surface plate and to be hardly displaceable in a direction perpendicular to the direction of depression;
• and
• a switch disposed within the case on the rear plate in a position opposing to said projection end of the projection member and operatively turned on by displacement of the knob as said knob is depressed toward said rear plate.