| 摘要 |
A chain door lock includes first part attached to a door adjacent the free edge of the door, a second part attached to the door jamb, and a chain attached to the second part and removably attached to the first part. The first part includes a horizontal spring chamber, a slide element within the spring chamber, a chain holder attached to the slide element, and a shock-absorbing coil spring between the slide element and the spring chamber. The second part includes a leaf spring. The chain is sufficiently long that the door may be partially opened without compressing either spring. The coil spring is sized to absorb a substantial impact, as from the body of a would-be intruder.
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