| 摘要 |
<p>A coupling piece (2) extends in a downwards direction from the lower tube (12) connected to the steering column tube (14) in the front frame unit (1). The coupling piece includes a first fixing part (21) with front and back walls (211, 212) which define jaws and are spaced apart along a first line extending in a radial direction relative to the front axle. The walls are divided in two by a first central axis extending parallel to the front axle. A connecting unit (3) has a first end secured to the bottom end of the rear fork (15) and includes a middle arm (36) extending in a forwards direction from this first end and a second fixing part (32) extending in a forwards direction from the arm and located at a distance from the first fixing part. The second fixing part has front and back walls (321, 322) which define jaws and are spaced apart along a second line extending in a radial direction relative to the front axle. The walls are divided in two by a second central axis extending parallel to the front axle. The first and second central axes are aligned on a rotation axis (X) so that when the rear fork travels through an angle relative to the front frame unit as a result of a shock caused by the back wheel hitting an obstacle, the second fixing part is rotated from a normal position in which the first and second lines are located in the same plane, into a deformed position in which the first or second line is located outside the normal plane. An elongated rotary part (4) extending along the rotation axis has left and right fixed regions making frictional contact with the two fixing parts in order to prevent these regions from rotating when the second fixing part is rotated between the normal position and a deformed position. An intermediate part (44) can rotate in order to allow the second fixing part to rotate into the deformed position and to allow a return force to be generated, urging the second fixing part back into its normal position so that the shock force is countered. A bearing is used to keep the intermediate part on the rotation axis when the second fixing part is rotated between the normal and deformed positions. A saddle pin tube (13) is connected at its top end to the saddle mounting (11) and slants downwards in the backward direction to its bottom end close to the rear axle.</p> |
