摘要 |
In a tractor operated piggyback railway trailer hitch including a vertical strut and a diagonal strut supporting a hitch head or fifth wheel, an improved bumper block assembly is provided, including at least one bumper block support plate pivotably mounted about a first pin in the hitch head, and a kingpin block laterally spaced from the bumper block support plate. The bumper block includes a generally vertical surface adapted to be contacted by a tractor, and a body portion including a first opening to receive a second pin. The bumper block is pivotably mounted about the second pin extending through the bumper block support plate and the bumper block. A third pin extends through the bumper block and said bumper block support plate. The third pin is designed to shear at a predetermined applied load. Thus, if the tractor applies a load to the third pin above the predetermined load, the third pin will shear off and the bumper block will pivot about the second pin, and the remainder of the hitch operating mechanism which might normally be damaged by such a hard impact is protected.
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