Telescoping boom assembly with longitudinally displaceable base boom section

Method of operating a telescoping boom of a material handling apparatus, said boom having a base boom section adapted to telescopingly receive an extensible boom section having a free end, said base boom section being pivotally attached to said material handling apparatus by means of a boom cradle having first and second laterally extending cradle arms, releasable means for securing said base boom section to said cradle arms, first stop means disposed intermediate the length of said base boom section and releasably attachable to said first cradle arm, and second stop means disposed on the end of said base boom section remote from the free end of said extensible boom section, said second stop means being selectively atachable to said second cradle arm, comprising:

• a. extending said extensible boom section relative to said base boom section;
• b. restraining the free end of said extensible boom section;
• c. releasing said means for securing said base boom section to said first and second cradle arms;
• d. releasing said first stop means from said first cradle arm;
• e. retracting said extensible boom section relative to said base boom section until said second stop means contacts said second cradle arm;
• f. securing said second stop means to said second cradle arm;
• and
• g. securing said means for securing said base boom section to said cradle arms.

Method of operating a boom of a material handling apparatus, said boom having a base boom section adapted to telescopingly receive an extensible boom section on the end of which is mounted a work implement, said base boom section being pivotally attached to said material handling apparatus by means of a boom cradle having first and second laterally extending cradle arms, releasable means for securing said base boom section to said cradle arms, first stop means disposed intermediate the length of said base boom section and releasably attached to said first cradle arm, and second stop means disposed on the end of said base boom section remote from the end of said extensible boom section, said second stop means being selectively attachable to said second cradle arm, comprising:

• a. extending said extensible boom section relative to said base boom section;
• b. restraining the end of said extensible boom section by securing said work implement to the ground;
• c. releasing said means for securing said base boom section to said first and second cradle arms;
• d. releasing said first stop means from said first cradle arm;
• e. retracting said extensible boom section relative to said base boom section until said second stop means contacts said second cradle arm;
• f. securing said second stop means to said second cradle arm;
• and
• g. securing said means for securing said base boom section to said cradle arms.

An extendible boom material handling vehicle comprising:

• a. a driven lower chassis;
• b. an upper structure rotatably supported from said driven lower chassis;
• c. a telescoping boom comprising a base boom section and at least one extensible boom section telescopingly received within said base boom section and having a free end adapted to receive a work implement;
• d. a boom support element supported by said upper structure, said boom support element comprising:
• (i) a boom cradle having first and second transverse cradle arms, said cradle arms extending perpendicularly of the axis of said telescoping boom;
• and
• (ii) means for releasably attaching said base boom section to said cradle arms;
• e. means for longitudinally displacing said base boom section relative to said boom cradle when said base boom section is released from engagement therewith;
• f. at least one first stop means secured to said base boom section intermediate the length thereof, said first stop means being releasably attachable to said first cradle arm;
• g. at least one second stop means secured to said base boom section adjacent the end thereof remote from the free end of said extensible boom section, said second stop means being releasably attachable to said second cradle arm;
• and
• h. said means for displacing said base boom section comprises means for reversably displacing said base boom section between a first position in which said first stop means is disposed adjacent said first cradle arm and a second position in which said second stop means is disposed adjacent said second cradle arm.