| 摘要 |
PROBLEM TO BE SOLVED: To facilitate attachment/detachment operation without the need for a large force in the case of attaching/detaching a battery pack by adopting an S-shaped spring from a conventional Ushaped spring so as to strengthen the initial pressure thereby obtaining sufficiently a holding force. SOLUTION: A battery pack 2 has an upper case 2a and a lower case 2b to contain a battery. A lock lever 3 provided turnably around a support 4 toward the battery pack 2 has a projection 6 engaged with a recessed part 5 provided to a telephone set main body 1. A spring 8 always energizes the lock lever 3 in the direction that the projection 6 engages with the recessed part 5. The S-shaped spring 8 is adopted. Thus, in the S characteristic of a weight with respect to the displacement of the clock lever, the initial pressure is high and in the case attaching/detaching the battery pack 2, the same force as the conventional U-shaped spring is enough. Thus, the operating range of the weight is narrower than that of the case with the U-shaped spring and while improving the attachment/detachment operability of the battery pack 2, the holding force is strengthened. |
