Patent ID: 6851149

Claim:
A drawbridge apparatus for selectively spanning an opening, such as over a river or ditch, between a first bridge approach and a second bridge approach, comprising: a bridge deck, said bridge deck sized to span the opening between the first bridge approach and the second bridge approach; a first base adjacent to said first bridge approach, said first base comprising a foundation structure positioned and configured to support a first end of said bridge deck such that a top surface of said first end of said bridge deck is substantially even with a top surface of the first bridge approach; a second base adjacent to said second approach, said second base comprising a foundation structure positioned and configured to support a second end of said bridge deck such that a top surface of said second end of said bridge deck is substantially even with a top surface of the second bridge approach; a support platform adjacent said first base; a lifting platform below said bridge deck; a plurality of scissor lifts positioned between said support platform and said lifting platform, each said scissor lift having a first and a second lift arm pivotally linked to one another, a lower end of said first arm pivotally attached to said support platform, a lower end of said second pivot arm pivotally linked to a scissors lift bar; a lifting beam attached to an end of said scissors lift bar; a drive means for providing straight line motion to said lifting beam for selectively raising or lowering said scissors lifts to thereby raise or lower said lifting platform with respect to the said support platform; a deck rack secured to the bridge deck; a deck drive motor secured to the lifting means; a deck pinion gear coupled to said deck drive motor and to said deck rack; a plurality of wheel trucks disposed on the top surface of said lifting means, the bridge deck slidably coupled on top of said lifting means via said wheel trucks; and a drive means to provide torque for said deck pinion gear to operatively engage said deck rack.