a first suction module and a second suction module, each of said first and second suction modules including a support frame defining a vacuum chamber and a vacuum unit supported on said support frame and communicating with said vacuum chamber, said vacuum unit including a rotating impeller and an exhaust cowling surrounding said impeller, wherein said impeller has an axis of rotation and is adapted to draw air from said vacuum chamber into said impeller in a direction generally parallel to said impeller axis of rotation, and is further adapted to discharge said drawn air from said impeller in a direction substantially perpendicular to said impeller axis of rotation, and wherein said exhaust cowling is adapted to redirect said discharged air from said impeller in a direction substantially parallel to said impeller axis of rotation, whereby a thrusting force is applied to said support frame in a direction opposite of the direction of said drawn air from said vacuum chamber; and

a hinge assembly pivotably connecting said first suction module to said second suction module, said hinge assembly facilitating nonplanar orientation of said first suction module with respect to said second suction module.