Harnischfeger Corporation

James N Johnson

James C Mayo, Sr

Robert A Fritsch

A mobile crane has a multisection telescopic boom and an optionally useable lattice jib storable alongside the boom with the base end of the jib adjacent the point end of the boom. Improved jib storage support means are provided to facilitate storing and installing the jib. Thus, one side of the boom base section is provided with a pair of longitudinally spaced apart jib storage support assemblies. Each support assembly is pivotally mounted so that it can be swung between a jib-supporting position and a stored position. Each support assembly includes a laterally extending member which is tiltable between a horizonal and a downward position so that the jib can be easily swung thereonto for storage and then subsequently locked into horizontal position, whereupon locking brackets secure the jib on the support assembly. The point end of the boom fly section and the base end of the jib are provided with cooperating disconnectable hinge members for attacing the jib to the boom so that the jib can be swung horizontally between stored and installed positions. The point end of the boom fly section and the base end of the jib are also provided with connection means for securing the jib to the boom.

Storage means for jib for telescopic boom of mobile crane

A mobile crane has a multisection telescopic boom and an optionally useable lattice jib storable alongside the boom with the base end of the jib adjacent the point end of the boom. One side of the boom base section is provided with a pair of longitudinally spaced apart jib storage support assemblies to facilitate storing and installing the jib. The point end of the boom fly section and the base end of the jib are provided with cooperating disconnectable hinge members for attaching the jib to the boom so that the jib can be swung horizontally between stored and installed positions. The point end of the boom fly section and the base end of the jib are provided with connection means, including a cylindrical rod on the boom fly section and cooperating journal bearings on the jib, for securing the jib to the boom in either axial aligned position or in downwardly tilted position, and adjustable strut means is detachably connected between the boom and the jib to limit the extent to which the jib can tilt downwardly. The jib is provided with a self-storing and self-erecting jib mast which is pivotally mounted on the upper side of the jib and cooperates with guy lines to support the jib during set-up and operation of the crane. Releasable locking means are provided on the boom fly section and the next adjacent boom section to prevent the extended boom sections from accidentally telescoping under the weight of the jib in the event of a hydraulic system failure.

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Cedar Rapids, IA, United States of America

James N Johnson