backside that is planar thereby facilitating mounting of the hinge block 32 to a planar surface such as the under surface of a toilet seat not shown the back plate 34 further includes a front side to which the retaining blocks 36 are coupled in some embodiments the back plate 34 and the retaining blocks 36 are manufactured as a single unit in other embodiments the back plate 34 and the retaining blocks 36 are separate components that are joined together via an appropriate polymer joining technique as known in the art in still other embodiments the hook component 26 and the hinge block 8 are designed to simplify the molding and manufacturing process yet maintain the desired hinge effect the retaining blocks 36 are generally positioned on the front side of the back plate 34 and are provided to support the rod components 28 of the hinge assembly 8 in some embodiments as shown in fig1 f the rod elements spans the distance between a pair of opposing retaining blocks 36 in other embodiments as shown in fig1 g the rod element comprises a pair of rod studs each rod stud being coupled to a single retaining block 36 of the hinge assembly 8 as shown in fig1 i the hook component 26 is tilted slightly downward and inward towards the back side 24 of the shield 20 thus the hook component 26 engages the rod component 28 from above wherein the downward force of the shield 20 maintains the engagement of the two components 26 and 28 although.