| 摘要 |
<p>Two beam control-levers (22, 23) situated above each other with a space apart are positioned on the plane of a symmetry. The front and back ends of the beam control levers (22, 23) are hinged to the beam (1). The front bearing of the top control lever and the back bearing of the bottom beam-control-lever are pivot bearings (39, 40) and the other two bearings (43, 43) are ball-and-socket bearings. A connecting piece (24) which is adjustable in length is supported between a beam control-lever and the frame. The axis of swing of the beam (1) is situated on the plane of symmetry, and slants downwards at an acute angle in the direction of travel.</p> |
