Editing Tokai MM9 series (section)

==Description==
The conductive ball is located inside a cage in the slider under tension from the main spring from above. When the switch is not pressed, the ball is held up partially by a prong in the slider and partially by a V-shaped groove in the first terminal.
When the switch gets pressed, the slider's support of the ball drops and the ball gets pressed towards two prongs of the second terminal. When the ball touches both terminals, the switch is closed.<ref name="yt"/>

The switches were described by the Tokai website as 「接点が回転するボールコンタクトスイッチ！」. "Ball contact switch with rotating contacts". The implication of is not clear; it could be suggesting that the ball rotation spreads out the contact wear, but it may simply be a very brief explanation of the operation. The switches have a comparatively short lifetime of only two million cycles; there are no flexible parts in the contact mechanism, which may be related. The website also classified the switches as 「メカニカルスイッチ」, "mechanical switch".

Switch travel is 2.5±0.3 mm. 「作動力」, "actuating force", is given as 100±30 g. This is not the actuation force but rather the peak/terminal force. The switch is progressive rate; the perceived action is progressive rate with knee, but in reality there is an instantaneous jump of around 25 cN at the actuation point, from around 45 cN to nearly 70 cN.<ref name="MM9-3-graph" /> Actuation occurs at this point, followed by a stiff overtravel region up to the stated 100 g mark.