| 摘要 |
The movement into a switching position which corresponds to the electric quiescent condition of the telephone set when the handset is on-hook (Fig. 2) of a plurality of contact springs (6) disposed in a hook switch housing (1) and interacting in groups by means of a common drive slide (14) guided vertically in relation to the housing is intended to be achievable with an extremely small drive force. For this purpose, the contact springs which can be moved by the drive slide (14) are in part elastically pre-tensioned in opposite directions to one another. A dedicated reset spring (17) which, in its rest position, holds the drive slide in one of its two locking positions is provided with an essentially rectangular cross-section profile (18) stiffened with an arc-shaped curve. For mechanical actuation of the hook switch in this design by replacing a handset on the telephone, the stiffening effect of the profile curve of the reset spring must first be counteracted. The reset spring then resists further movement with only minimal, slightly increasing force. <IMAGE>
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