Space key

Claim 2

A space key to actuate reliably a switch disposed under a guide plate, said key comprising: an elongated upper cover having downwardly extending protuberances, a lower guide plate having upright portions in slidable contact with said protuberances of said upper cover to guide downward movement of said upper cover, a spring disposed between said upper cover and said guide plate, and a stabilizer rod having a center stem portion extending in the lateral direction of said upper cover and rotatably received by one wall portion of said upper cover and generally Z-shaped end portions, the pointed ends of which are pivotably received in corresponding notches formed in upright portions of said guide plate, wherein said upper cover moves down without inclination in response to depression force applied thereto at any portion.

Claim 3

A space key to actuate reliably a switch disposed under a guide plate, said key comprising: an elongated upper cover having downwardly extending protuberances, a lower guide plate having upright portions in slidable contact with said protuberances of said upper cover to guide downward movement of said upper cover, a spring disposed between said upper cover and said guide plate, and a stabilizer rod having a center stem portion extending in the lateral direction of said upper cover and rotatably received by one wall portion of said upper cover and generally Z-shaped end portions, the pointed ends of which are pivotably received in corresponding notches formed in upright portions of said guide plate, wherein said upper cover moves down without inclination in response to depression force applied thereto at any portion.

Claim 4

A space key to actuate reliably a switch disposed under a guide plate, said key comprising: an elongated upper cover having downwardly extending protuberances, a lower guide plate having upright portions in slidable contact with said protuberances of said upper cover to guide downward movement of said upper cover, a spring disposed between said upper cover and said guide plate, and a stabilizer rod having a center stem portion extending in the lateral direction of said upper cover and rotatably received by one wall portion of said upper cover and generally Z-shaped end portions, the pointed ends of which are pivotably received in corresponding notches formed in upright portions of said guide plate, wherein said upper cover moves down without inclination in response to depression force applied thereto at any portion.

Claim 5

The space key as specified in claim 1 further including: a keep plate secured to the underside of said upper cover to rotatably receive said staBilizer rod together with a stepping portion of said upper cover, which has downwardly extending wall portions in slidable contact with the upright portions of said guide plate.

Claim 6

The space key as specified in claim 1, wherein said notches are located at about the center of the operation range of compression and expansion of said spring.

Claim 7

In a space key comprising an upper cover, a lower guide plate, and a spring disposed between said upper cover and guide plate to space one away from the other, and constructed so that in response to depression of said upper cover, a switch mounted on the underside of said guide plate and coaxial with said spring is actuated, the improvement wherein: said upper cover has, in its inside lower portion, a stepping portion extending in the lengthwise direction along one of the longer downwardly extending walls and is formed with plate-like protuberances close to the lateral end portions of said upper cover; a keep plate is secured inside said upper cover extending between said plate-like protuberances which has downwardly extending laterally elongated wall portions one of which opposing said stepping portion has an outwardly extending curved portion; said guide plate has upright end portions, each formed with a notch, which are slidably in contact with the corresponding plate-like protuberances, and has further provided upright leaf portions so as to be in slidable contact with the corresponding wall portions of said keep plate; and a stabilizer rod having Z-shaped end portions is disposed so that its straight center portion is received between said stepping portion of said upper cover and said curved portion of said keep plate and each of said Z-shaped pointed end portions is movably received in a corresponding notch formed in said guide plate.

Claim 8

In a space key comprising an upper cover, a lower guide plate, and a spring disposed between said upper cover and guide plate to space one away from the other, and constructed so that in response to depression of said upper cover, a switch mounted on the underside of said guide plate and coaxial with said spring is actuated, the improvement wherein: said upper cover has, in its inside lower portion, a stepping portion extending in the lengthwise direction along one of the longer downwardly extending walls and is formed with plate-like protuberances close to the lateral end portions of said upper cover; a keep plate is secured inside said upper cover extending between said plate-like protuberances which has downwardly extending laterally elongated wall portions one of which opposing said stepping portion has an outwardly extending curved portion; said guide plate has upright end portions, each formed with a notch, which are slidably in contact with the corresponding plate-like protuberances, and has further provided upright leaf portions so as to be in slidable contact with the corresponding wall portions of said keep plate; and a stabilizer rod having Z-shaped end portions is disposed so that its straight center portion is received between said stepping portion of said upper cover and said curved portion of said keep plate and each of said Z-shaped pointed end portions is movably received in a corresponding notch formed in said guide plate.