| 摘要 |
<p>A door retarder to prevent movement of an unlocked railway freight door includes a spring urging a braking cam roller into a pivoted braking shoe that engages a door support rail. An operating handle has a double lobe cam to operate a linkage and move the braking cam roller away from the braking shoe to allow the door to move freely into and from a car door opening when the operating handle is rotated from a normal, upright position. When released, the operating handle returns to the normal position for retarding door movement.</p> |
