would occur as gear 22 is driven by the motor 12 it will finally reach the angle of rotation such that the opening 58 will be opposite projection 54 as shown in fig7 and 8 when this occurs projection 54 will drop abruptly into the opening 58 due to the sheer face on the opening relative to the projection this abrupt motion of spring 30 forces shaft 24 rapidly to the right fig7 this rapid motion to the right quickly disengages drive spring 36 from its matching vane 40 and also at the same time moves pin 42 out of alignment with star wheel 44 this rapid disengagement of drive spring 36 from vane 40 imparts a rotary motion to disk 38 because of the skewed vanes which now has no impediment to its free rotation disk 38 will rotate freely on shaft 24 until friction brings it to a stop in some random position the disk 38 vane 40 and pin 42 are all effectively one unit and rotate together and all these parts are balanced carefully so that the final position of the disk will not be affected by gravity the disengagement of the vanes 40 from drive spring 36 and the rotation of the disk 38 and the disk 39 s gradual stop is rapid compared to the rotation of gear 22 which is driven at a slow speed by the motor 12 after the disk 38 comes to.