Abstract: A pivot assembly has a pivot support member with a keyway. The keyway has two oppositely directed longer keyway wings extending from a middle section and the middle section has two oppositely directed shorter keyway wings extending in a direction transverse to that of the longer keyway wings. The shorter keyway wings have convexly radiused ends. The pivot assembly also has a pivot with an attachment portion and a key projecting rearwardly from the attachment portion. The key has a rearward section with oppositely directed longer key wings which are longer than the shorter keyway wings but sufficiently short to allow the longer key wings to pass through the keyway. The key also has a middle section between the rearward section and the attachment portion. The middle section has oppositely directed shorter key wings with convexly radiused ends. The shorter key wings extend in a direction aligned with that of the longer key wings.