The alarm clock escapement mechanism is a mechanism that connects the transmission system and vibration system. Its function is to transfer the energy of the primary system to the vibration system, in order to maintain the constant amplitude vibration of the vibration system; And transmit the vibration frequency of the vibration system to the pointer mechanism to achieve the purpose of measuring time. There are many types of escapement mechanisms, which can be divided into two categories based on their degree of connection with the vibration system Non free escapement mechanism: The escapement mechanism and vibration system often maintain a kinematic connection. It includes straight forward, backward, and I-wheel escapement mechanisms Free style escapement mechanism: Only in the release and transmission stages, the escapement mechanism and the vibration system maintain a kinematic connection, while the vibration system is in a free motion state in other stages. It includes pin type, fork tile type, and astronomical clock type escapement mechanisms.

① Backward escapement mechanism: widely used for high-precision pendulum clocks. Its fork tile locking surface and punching surface are on the same plane (working surface); The working surface of the tile is a cylindrical surface, and its center does not coincide with the rotation center of the escapement fork; The working surface of the tile is a flat surface. The fork tile and escapement fork are integrated. After passing the punch, the fork shoe working surface will force the escape wheel to retreat by an angle.

② Fork tile escapement mechanism: One of the most widely used escapement mechanisms. During operation, the escapement wheel obtains energy from the transmission system, which is transformed into impulse transmission to the escapement fork through the action of the escapement wheel teeth and the fork pad (in or out of the pad); Through the interaction between the fork of the escapement fork and the swing pin on the impact disc of the double disc, the impulse is transmitted to the vibration system. The safety disc and fork head nail of the double disc, as well as the horn mouth of the swing nail and escapement fork, are safety devices that ensure the normal operation of the mechanism.

③ Pin type escapement mechanism: The difference from the fork shoe escapement mechanism is that two cylindrical pins are used instead of the fork shoe on the escapement fork, and the impulse is only transmitted along the contact surface of the escapement gear teeth. This type of escapement mechanism has a simple structure, low accuracy requirements, and is easy to manufacture. It is often used in alarm clocks and low accuracy meters, commonly known as the coarse horse structure. The vibration system serves as a mechanism for time reference. The vibration period of the vibration system multiplied by the number of vibrations in the measured process is the time that the process has experienced. The commonly used vibration systems for mechanical clocks include pendulums, torsion pendulums, and cycloidal vibration systems.