Alarm clock

A rotatable alarm clock comprising

• a base;
• a hemispherical socket attached on the base and including an inner tab projected from an inner periphery thereof;
• a shaft passing through an axis defined in the hemispherical socket and having two distal ends attached to the hemispherical socket;
• a tube which is shorter than the shaft being rotatably positioned around a middle portion of the shaft;
• a clock body being rotatably positioned around the tube and including an alarm switch thereon;
• a first hemispherical cover being firmly attached around the tube and received in a space defined between the alarm body and the hemispherical socket, said first hemispherical cover including an outer tab projected from an outer periphery thereof;
• a plurality of second hemispherical covers, each of which is received one by one, being rotatably and uniformly positioned around the shaft and received in a space defined between the first hemispherical cover and the hemispherical socket, each of the second hemispherical covers including an inner tab projected from an inner periphery thereof and an outer tab projected from an outer periphery thereof;
• a motor which has a mandrel being firmly positioned in the alarm body;
• a drive gear being firmly attached around a mandrel of the motor;
• a driven gear being firmly attached around the tube;
• a spring-biased compound gear meshed to the drive gear;
• a speed-reducing gear set meshed with the driven gear;
• a normally-closed mercury switch being positioned in the alarm body;
• whereby the spring-biased compound gear is engaged to the speed-reducing gear set when the motor rotates, thus when a preset alarm time is coming, the alarm clock alarms and the motor is activated to rotate to drive the first hemispherical cover and the plurality of second hemispherical covers to rotate with respect to the shaft via a transmission through the drive gear, the spring-biased compound gear, the speed-reducing gear set, and the driven gear, until the outer tab of an outer most of second hemispherical covers abuts against the inner tab of the hemispherical socket, which in turn causes the alarm body to rotate with respect to the tube thus turning off the mercury switch and stopping the rotation of the motor, which in turn causes the spring-biased compound gear to disengage from the speed-reducing gear set, thereafter a user rotates the first hemispherical cover and the plurality of second hemispherical covers back to their original positions and turns off the alarm by operating the alarm switch.

A rotatable alarm clock comprising

• a clock body rotatably positioned around a tube which is rotatably positioned around a shaft which is firmly fixed in an inner space of a hemispherical socket which is firmly fixed on a base;
• a motor firmly positioned in the clock body and including a mandrel;
• a transmission means connected between the mandrel of the motor and the tube;
• a first hemispherical cover firmly attached around the tube and including an outer tab projected from an outer periphery thereof;
• at least a second hemispherical cover rotatably positioned around the shaft and including an outer tab projecting from an outer periphery thereof and an inner tab projected from an inner periphery thereof, the inner tab of the at least one second hemispherical cover abutting against the outer tab of the first hemispherical cover when the first hemispherical cover is driven to rotate for substantially a half circle;
• a control circuit for activating the motor to rotate when a preset alarming time is coming and stopping rotation of the motor when the clock body rotates;
• whereby the motor rotates to drive the first hemispherical cover and the at least one second hemispherical cover to rotate until the at least one second hemispherical cover is blocked by the hemispherical inner tab, thereafter the clock body rotates and causes the control circuit to stop the rotation of the motor.