| 摘要 |
A letterbox has height adjustable conveyors 6, 7 for conveying mail of different thicknesses and object detection means. Two conveyor are provided, preferably in the form of rollers which may be rubber coated. The object detection means may comprise a switch activated by the opening of a flap. Conveyor moving means 8 which adjust the height of at least one conveyor preferably comprise a pivoting arm upon which a conveyor is mounted and a rotatable cam 14 which causes the arm to pivot such that the conveyor means are moved between open and object engaging positions. The cam will not activate more than twice in response to a single signal from the detector. After two activations, if the detector still detects an object, alarm means may send an alarm to a variety of devices such as a telephone or camera. In use the apparatus prevents portions of mail remaining on the exterior of a letterbox. |
