| 主权项 |
1. A tow dolly releasably attached to and towable behind a towing vehicle having at a rearward end portion a receiver type towing hitch defining a rearwardly opening box beam channel, the tow dolly comprising in combination:
a dolly frame having plural spaced apart transverse frame beams and a tow beam having a forward end portion carrying a receiver hitch insert for releasable engagement with the receiver type towing hitch of the towing vehicle; an axle having wheels and tires at each opposing end portion to support the dolly frame spacedly above a supporting surface; a suspension interconnecting the dolly frame and the axle, the suspension having,
a swing arm with a forward end portion and a rearward end portion, the forward end portion pivotally interconnected to the dolly frame so that the rearward end portion may pivot towards the dolly frame and away from the dolly frame,connecting means positionally securing the axle to the swing arm spacedly adjacent the rearward end portion,a pneumatic apparatus communicating between the dolly frame and the swing arm to pivot the swing arm relative to the dolly frame responsive to axial expansion and contraction of the pneumatic apparatus, andpneumatic lines communicating with the pneumatic apparatus and a pneumatic valve to supply pressurized air to the pneumatic apparatus and to drain pressurized air from the pneumatic apparatus; a support frame carried spacedly above the dolly frame that is vertically adjustably positionable responsive to the axial expansion and contraction of the pneumatic apparatus. |
