pat-on-the-back

"A self-congratulatory apparatus having a simulated human hand carried on a pivoting arm suspended form shoulder supported member. The hand is manually swingable into and out of contact with the user's back to give an amusing or an important pat-on-the-back." (Abstract of U.S. patent 4,608,967 issued on September 2, 1986 http://worldwide.espacenet.com/publicationDetails/biblio?FT=D&CC=US&NR=4608967A)