Patent ID: 6609622
Filing Date: 2003-08-26
Classification: B66C,E02F

Abstract:
A bulldozer/pipelayer apparatus including a main frame with an engine and a ground engaging attachment disposed on a forward portion of said main frame for engaging and displacing soil or heavy objects when used in a bulldozer mode of operation, and a pipelayer attachment including a boom and boom and load winches for lifting and transporting sections of pipe when used in a pipelayer mode of operation, said apparatus comprising:right and left side frames each having a respective drive means attached thereto and engaging the ground for propelling the apparatus in a direction of travel, wherein said right and left side frames are attached to respective lateral portions of the main frame and are free to oscillate vertically as the apparatus traverses irregular terrain when in the bulldozer mode of operation and wherein the boom is pivotally mounted to only one of said side frames and extends transversely to the direction of travel; an equalizer bar having first and second opposed ends and a center portion, wherein said equalizer bar is pivotally coupled to the main frame and the first and second ends of said equalizer bar are respectively coupled to said right and left side frames; releasable locking means mounted to said main frame and engaging said equalizer bar when in the pipelayer mode of operation for preventing vertical oscillation of said side frames to provide stability for lifting and transporting sections of pipe and for releasing said equalizer bar and allowing vertical oscillation of said side frames when in the bulldozer mode of operation, wherein said locking means includes first and second hydraulic cylinders each having an extendible ram for engaging said equalizer bar for limiting vertical oscillation of said side frames when lifting and transporting sections of pipe over irregular terrain and maintaining said equalizer bar level while preventing vertical oscillation of said side frames when the bulldozer/pipelayer apparatus traverses level ground; and operator responsive input means for selecting either the pipelayer mode of operation, wherein said equalizer bar is prevented from vertical oscillation and said boom and load winches are automatically rendered operable, or the bulldozer mode of operation, wherein said equalizer bar is free to oscillate vertically and said boom and load winches are automatically locked.