Two-way extendable crane trolley

A two-way extendable trolley comprising

• a trolley frame and wheel means for supporting said trolley frame, said wheel means being adapted for travel along primary track means, means for driving said wheel means along said primary track means, hoisting means mounted on said trolley frame,
• a first horizontally elongated trailer frame slidably mounted on said trolley frame, said first trailer frame having a first end extending beyond a first end of said trolley frame, first auxiliary wheel means for supporting said first end of said first trailer frame, said first auxiliary wheel means being adapted for travel along said primary track means, a first auxiliary hoisting means mounted on said first trailer frame, and means for horizontally extending said first trailer frame outwardly from said trolley frame and retracting said first trailer frame inwardly toward said trolley frame, and
• a second horizontally elongated trailer frame slidably mounted on said trolley frame, said second trailer frame having a first end extending beyond a second end of said trolley frame, second auxiliary wheel means for supporting said first end of said second trailer frame, said second auxiliary wheel means being adapted for travel along said primary track means, a second auxiliary hoisting means mounted on said second trailer frame, means for horizontally extending said second trailer frame outwardly from said trolley frame and retracting said second trailer frame inwardly toward said trolley frame, said first trailer frame and second trailer frame being adapted for extending in opposite directions for each other.