Hinge assembly

A tonneau cover is mounted to the cargo area of a pickup truck by a hinge mechanism positioned at the forward end of the pickup truck cargo area. The hinge assembly has two major components. The first component is a mounting plate that is affixed to each sidewall of the cargo area near the forward extent of the cargo area. The mounting plate includes an alignment mechanism and a mechanism for clamping the second component onto the mounting plate. The mounting plate further includes a beveled upper flange to assist in guiding the removable component onto the mounting plate during installation. The removable component includes a base plate, a number of arms forming an articulating mechanism, and a bracket for mounting to the tonneau cover. The base plate includes an angled lower segment for cooperating with the beveled upper section of the mounting plate to aid in guiding the removable component onto the mounting plate. The base plate also includes slots for engagement by the clamping mechanism of the mounting plate. The articulating mechanism is configured to open the tonneau cover in a nearly vertical direction initially, prior to rotation of the tonneau cover to an open position. With the removable component engaged on the mounting plate, and prior to engagement of the clamps, the hinge assembly is configured so that the tonneau cover can be opened from the rear of the pickup truck cargo area without the removable component becoming disengaged from the mounting plate. With the tonneau cover thus in the open position, an installer can reach in from the side of the truck cargo area and engage the clamps to secure the removable component to the mounting plate. The clamps are configured to accept a tool, but can be engaged without the use of tools.