An energy-storing unit with a forcing mechanism, the energy-storing unit comprising: an eccentric cam linked with a drive shaft and moving in synchronization therewith; a hoist case which is linked with the eccentric cam and which reciprocates linearly in synchronization with the eccentric cam; a spring attached to the hoist case; an energy-storing case which is linked with the hoist case through the spring and which reciprocates linearly in synchronization with the hoisting case; a crank which is linked with the energy-storing case and which rotates in synchronization with the energy-storing case; and a catch that is engaged with the crank at a predetermined standby position to lock a rotation of the crank and to compress the spring, the forcing mechanism comprising: a protrusion attached to the eccentric cam; and a loading cam attached to the energy-storing case, characterized in that: the forcing mechanism further comprises a bearing attached to a tip of the protrusion; the loading cam contacting with the bearing to rotate the crank through the energy-storing case, and move the catch to the standby position; and wherein there is no change in a distance from a rotation center of the eccentric cam to a contact point between the bearing and the loading cam even if a rotation of the eccentric cam advances. an eccentric cam linked with a drive shaft and moving in synchronization therewith; a hoist case which is linked with the eccentric cam and which reciprocates linearly in synchronization with the eccentric cam; a spring attached to the hoist case; an energy-storing case which is linked with the hoist case through the spring and which reciprocates linearly in synchronization with the hoisting case; a crank which is linked with the energy-storing case and which rotates in synchronization with the energy-storing case; and a catch that is engaged with the crank at a predetermined standby position to lock a rotation of the crank and to compress the spring, the forcing mechanism comprising: a protrusion attached to the eccentric cam; and a loading cam attached to the energy-storing case, characterized in that: the forcing mechanism further comprises a bearing attached to a tip of the protrusion; the loading cam contacting with the bearing to rotate the crank through the energy-storing case, and move the catch to the standby position; and wherein there is no change in a distance from a rotation center of the eccentric cam to a contact point between the bearing and the loading cam even if a rotation of the eccentric cam advances. a protrusion attached to the eccentric cam; and a loading cam attached to the energy-storing case, characterized in that: the forcing mechanism further comprises a bearing attached to a tip of the protrusion; the loading cam contacting with the bearing to rotate the crank through the energy-storing case, and move the catch to the standby position; and wherein there is no change in a distance from a rotation center of the eccentric cam to a contact point between the bearing and the loading cam even if a rotation of the eccentric cam advances. the forcing mechanism further comprises a bearing attached to a tip of the protrusion; the loading cam contacting with the bearing to rotate the crank through the energy-storing case, and move the catch to the standby position; and wherein there is no change in a distance from a rotation center of the eccentric cam to a contact point between the bearing and the loading cam even if a rotation of the eccentric cam advances.