| 摘要 |
Speed restricting bumps for installation across a road comprise a contact plate 17 that can be selectively locked in position or be deflected vertically and progressively by a passing road vehicle in relation to a base plate 18. With the contact plate locked into the raised position a passing road vehicle will experience a jolt as it traverses the device. When the contact plate is unlocked the passing vehicle will deflect vertically and progressively the contact plate due to the differential angles of the surfaces of the contact plate 17 and base plate 18. The weight of the road vehicle is either then borne by, or transferred to, the base plate 18, so that the road vehicle passes by relatively unhindered. In an alternative form the contact plate 3 is normally level with the road surface, so that the physical jolt is only imparted when the contact plate is unlocked, and can therefore be deflected vertically so that a dip for the road vehicle to drop into is formed. The locking and unlocking of the contact plate is made by a controlling mechanism whose operation is determined by a speed measuring device. There may be a number of narrow contact plates adjacent each other, or one wide contact plate. |
