| 主权项 |
1. A height adjusting mechanism for changing the height of a load supporting portion of a trailer with respect to an external surface, the trailer including a trailer frame having a rear end, the trailer frame supporting the load supporting portion of the trailer, the height adjusting mechanism comprising:
an axle rotatably connected to the trailer frame and mounted thereto for rotation about a pivot axis that extends through the axle and remains in a fixed position with respect to the trailer frame between a towing position and a loading position, the axle having a first portion and a pair of axle shafts that are resiliently mounted with respect to the first portion for rotation over a limited angular range of motion and are biased toward a neutral position; a pair of opposed pivot arms, each having a first end connected to the one of the axle shafts of the axle and a second end rotatable about the pivot axis, the second ends of the pivot arms each defining a respective wheel axis, the pivot arms rotatable in response to rotation of the axle between the towing position, wherein the load supporting portion of the trailer is disposed at a first elevation with respect to each respective wheel axis and the rear end of the trailer is vertically spaced from the external surface, and the loading position, wherein the load supporting portion of the trailer is disposed at a second elevation with respect to each wheel axis, the rear end of the trailer is positioned adjacent to the external surface, and the pivot arms are rotatable with the axle shafts of the axle in response to rotation of the axle shafts with respect to the first portion of the axle; an arcuate flange connected to the first portion of the axle adjacent to one of the pivot arms for rotation in unison with the axle, the flange extending from a first end that defines a first stop to a second end that defines a second stop; and a restraining element connected to the trailer frame and selectively engageable with the first stop and the second stop, wherein engagement of the restraining element with the first stop restrains the axle from rotating toward the loading position from the towing position and engagement of the restraining element with the second stop restrains rotation the axle from rotating toward the towing position from the loading position. |
