Adjustable bow for a truck tonneau cover

Claim 1

An adjustable bow assembly for a tonneau cover assembly on a truck bed of the type having a front wall, an end wall, and an opposing sidewalls therebetween, said tonneau cover assembly comprising in combination a support frame on said truck walls, said support frame comprising an elongated base having opposing frame portions on said respective opposing sidewalls of said truck bed, an enclosed channel area extending from said base, a flange element on said channel area in vertically spaced relation to said base, adjustable bows comprising an elongated rail section, said rail section having first and second sidewalls in spaced parallel relation to one another, a transverse wall extending between said first and second sidewalls, each of said first and second sidewalls terminating in a transversely inwardly directed flange having a return flange thereon extending from each of said first and second sidewalls defining mounting channels therebetween, an inwardly projecting rib on said transverse wall, a pair of adjustable extension elements threadably secured within said respective mounting channels, means for advancement of said extension elements within said channels, and means for positioning said adjustable bows within said support frame.