The half disme said to have been struck from silverware supplied by George Washington. They have also been called the Martha Washington half dime due to Liberty appearing to look similar to Martha Washington. Current researches have shown these stories to be old wives tales. A good writeup on these can be found in Heritage's April 2006 sale.
These have diagonally reeded edges which slope down to the right (the image below is a mirror image) with the obverse upward as shown in the photo below.
Technically, these are regular issues and not patterns. At least 1500 were struck, of which, a few hundred still survive. There are over a dozen known in various degrees of uncirculated with the following probably being the top 5.
1) Stacks 10/88, Parino, Knoxville Collection, Cardinal Foundation-StacksBowers 1/13 - NGC68
2) Brand-J.C. Morgenthau 10/33, Starr-Stack's 10/1992, Superior 7/93, Heritage, 4/2006, Heritage 1/13 FUN, Heritage 8/14 ANA, R. Rodriguez - PCGSSP67
3) Malcolm O.E. Chell-Frost 1948 ANA, Pittman-Akers 10/1997
4) Charles A Cass, Princeton University
5) Dr. Judd; Paramount Auction '80, Jimmy Hayes-Stack's 10/95, Clifford Mishler, StacksBowers 8/13 ANA - PCGS66
A single example is known in copper, with plain edge, J8/P8 and is ex Mickley (Mason & Co 11/1878), Parmelee (6/1890), Morris (4/1905), S.H. Chapman, Newcomer, Lohr, Paramount 4/1965 Century sale, Roper-Stacks 12/83, Partrick-Heritage 1/15 FUN - NGCAU55BN. It is illustrated below courtesy of Heritage.
It has a deep groove on Liberty's cheek.
For additional historical information on 1792 coinage, click here.
Photos of Judd 7 courtesy of the Museum of the American Numismatic Association - inventory number 1978.332.3 and is the example that was stolen from that institution in 2011.