| 摘要 |
<p>The use of the device is to secure the key bit in its originally inserted position within the key hole and prevent it from dropping out when the door is slammed. The device may be applied in various alternatives, such as fitting a tapered elastic plug (3) into the shaft of key (1). A further alternative envisages the use of a plastic door plate with a set of yielding tongues around the area of the keyhole. A further alternative uses, on the lock casing in the keyhole area, elastic tongues or a sleeve which hold the key in position by a clamping action around its shaft.</p> |
