| 摘要 |
A trackerball arrangement includes a ball rotatably mounted with respect to a housing; a plurality of supports arranged to locate the ball in a predetermined operable position relative to the housing, at least one of the supports being mounted for movement away from the other supports; and being urged towards said other supports against a stop by the action of a resilient member acting upon it; whereby pressure which is applied via the ball to the supports causes movement of the supports when the applied pressure exceeds a threshold value which overcomes the force exerted by the resilient member. The movement allows lateral movement of the ball away from the other supports. The support is mounted on a spring loaded pivotable arm with an engagement part biased into contact with the surface of the ball and part of the pivotable arm is arranged to actuate an electrical switch mechanism.
|
