Alarm setting apparatus for timepieces

An alarm setting device for a timepiece comprising:

• an alarm intermediate wheel that is assembled in a wheel train of a timepiece and is interlocked with time hands;
• an alarm setting wheel held by a main plate coaxially with said alarm intermediate wheel in a freely rotatable manner, and which serves to set an alarm triggering time;
• an alarm setting cam that is disposed coaxially with and between said alarm intermediate wheel and alarm setting wheel and being rotatable by being drawn by the alarm intermediate wheel, said alarm setting cam further being freely movable in an axial direction;
• a loading spring for pressing the alarm setting cam toward the alarm setting wheel;
• wherein:
• on one side of said alarm setting cam which faces the alarm intermediate wheel, at least one protrusion is provided, while on the other side thereof that faces the alarm setting wheel, at least two alarm engaging portions are provided;
• on one side of said alarm intermediate wheel that faces the alarm setting cam, at least one loose joint for engaging with said protrusion of the alarm setting cam is provided, and this loose joint is longer in its length in a circumferential direction than that of the protrusion of the alarm setting cam in order to drive the alarm setting cam to rotate by dragging said alarm setting cam, thereby making it possible for the protrusion to rotate along the circumferential direction for a predetermined extent within the loose joint;
• on one side of the foregoing alarm setting wheel that faces the alarm setting cam, at least two alarm fingers for moving the alarm setting cam towards the axial direction during the alarming operation by engaging with said engaging portions of the alarm setting cam are provided;
• said alarm fingers and the engaging portions which are provided on the mutually facing surfaces of the alarm setting cam and the alarm setting wheel each are provided with a sloped depression and a sloped shoulder for making it possible to effect the alarm setting operation in a clockwise as well as in a counterclockwise direction;
• and
• a projection and a recess that can be engaged with said projection are formed, adjacent to said depression on top of the alarm finger and adjacent to the depression of the corresponding engaging portion, and upon engagement of the projection with the recess, the protrusion of the alarm setting cam is pressed against a wall surface of the loose joint of the alarm intermediate wheel, whereby the alarm intermediate wheel and the alarm setting cam are securely engaged at the time of triggering the alarming operation and high precision in alarm setting is achieved.