Removable vehicle chassis sub-frame with engine

Abstract

A heavy duty motor vehicle has a main frame with a forward axle and steerable ground wheels. A power unit sub-frame carrying a rear axle is releasably secured to the main frame, and includes an engine assembly which is located at an intermediate position between the axles. The unit may also include a fifth wheel assembly whereby it becomes a towing vehicle for a further trailer unit or units.

I claim: 
     
       1. In a motor vehicle: a frame having frame side elements and cross elements, including at least one fixed intermediate cross element, connecting the side elements;   a cab mounted to the frame;   a fifth wheel mounted to the frame rearwardly of the cab for connection to a trailer that overhangs the frame rearwardly of the cab;   a front axle having steerable ground wheels thereon;   front suspension air bag means for the front axle interposed between the front axle and the side elements;   a power unit comprising a power unit sub-frame including a transverse forward rod and side rods fixed to and extending rearwardly of the forward rod below the side elements, the side rods having rearward distal ends;   a single hitch means, located rearwardly of the front axle, releasably connecting the center of the forward rod to the center of the intermediate cross element;   a rear axle assembly, having ground wheels and having a differential assembly, secured to the distal ends of the side rods;   rear suspension means interposed between the side rods and the side elements proximate to the rear axle assembly;   means securing the rear suspension means to the side rods and the side elements including releasable securing means securing the rear suspension means to at least one of the side rods and the side elements;   engine mounting means extending between the side rods between the hitch means and the rear axle assembly; and   an engine assembly, including an engine, secured on said mounting means and located between the hitch means and the rear axle assembly.   
     
     
       2. The invention of claim 1, wherein: the rear suspension means comprises a series of air bags.   
     
     
       3. The invention of claim 1, and: a stabilizer rod releasably secured between the differential assembly and the frame.   
     
     
       4. The invention of claim 1, and: a stabilizer rod secured between the frame and the front suspension means.   
     
     
       5. In a vehicle: a frame having side elements;   a front axle, having steerable ground wheels thereon, secured to forwardly projecting frame pivot arms, the frame pivot arms being pivotally secured at their front ends to the frame side elements;   yieldable suspension means mounted between the pivot arms and the frame side elements;   hitch means spanning the frame side elements rearwardly of the front axle;   a power unit, including a sub-frame having hitch connection means, releasably engaged with and extending rearwardly of the hitch means;   a rear axle, having ground wheels, secured to the sub-frame rearwardly of the hitch means;   yieldable suspension means releasably interposed between the sub-frame and the main frame; and   an engine assembly mounted to the sub-frame between the hitch means and the rear axle.   
     
     
       6. The invention of claim 5, wherein: the yieldable suspension means comprise air bags.   
     
     
       7. The invention of claim 5, and: a power train assembly operatively mounted on the sub-frame.   
     
     
       8. The invention of claim 5, and: a longitudinally movable fifth wheel assembly on the main frame. .Iadd. 9. In a motor vehicle:   a frame having side frame elements and cross elements connecting the side elements;   a cab mounted to the frame;   a fifth wheel mounted to the frame rearwardly of the cab for connection to a trailer that overhangs the frame rearwardly of the cab;   a front axle having steerable ground wheels thereon;   yieldable front suspension means for the front axle disposed between the front axle and the side elements;   a rear axle assembly, having ground wheels thereon and having a differential assembly;   hitch means located between the front and rear axles;   a power unit comprising a power unit sub-frame including side rods extending rearwardly of the hitch means below the side elements, the side rods having forward ends and rearward distal ends, and the rear axle assembly being secured to the distal ends of the side rods;   the side rods being releasably connected by the hitch means with the side frame elements;   rear suspension means disposed between the side rods and the side elements proximate to the rear axle assembly;   means securing the rear suspension means to the side rods and the side elements including releasable securing means securing the rear suspension means to at least one of the side rods and the side elements;   engine mounting means extending between the side rods between the hitch means and the rear axle assembly; and   an engine assembly, including an engine, secured to the engine mounting means and located between the hitch means and the rear axle assembly.   
     
     
        .Iaddend..Iadd. 10.  In a vehicle: a frame having side elements;   a front axle, having steerable ground wheels thereon, secured to forwardly projecting frame pivot arms, the frame pivot arms being pivotally secured at their front ends to the frame side elements;   yieldable suspension means mounted between the pivot arms and the frame side elements;   a rear axle having ground wheels thereon;   hitch means on the frame side elements located between the front and rear axles;   a power unit, including a sub-frame having hitch connection means, releasably engaged with and extending rearwardly of the hitch means, the rear axle being secured to the sub-frame rearwardly of the hitch means;   yieldable suspension means releasably disposed between the sub-frame and the main frame; and   an engine assembly mounted to the sub-frame between the hitch means and the rear axle. .Iaddend.