| 摘要 |
A movable subframe for tractor-trailers, commonly referred to as a slider, includes a retractable pin mechanism having improved locking pins (149) for locking the movable subframe in a selected position relative to the tractor- trailer body. The improved pin includes a tapered or truncated conical-shape d portion (151) which nests in a tapered enclosure (164) when the pins are in the fully extended or locked position. When one or more of the pins of the retractable pin mechanism become jammed in the locked position due to slight misalignment between the respective slider and trailer body openings through which each pin extends when in the locked position, a generally uniformly distributed contact surface pressure exists between the truncated conical- shaped portion (151) of the pin and the tapered enclosure. Other parts of th e pin are subjected to relatively intense contact point pressures. Such pressures in turn cause shear forces which resist retraction of the jammed pins. However, a vehicle operator attempting to free the pins needs only to slightly retract the pin mechanism and clearance is created between the tapered portion of each jammed pin and the tapered enclosure, much like pulling two tapered cups apart when one is stored within the other. Once clearance occurs, the areas of contact point pressure on the pin at other locations also are relieved. The retraction of the jammed pins of the presen t invention is achieved without overexertion on the part of the vehicle operat or and/or damage to the retractable pin mechanism.
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