Weckeler
The Weckeler, also called a Weckelerpfennig, is a one-sided silver Palatine pfennig coin of the 14th and 15th century, which was also called the Wegkpfennig in the local dialect. It occurs both as a Schüsselpfennig and as a non-domed, planar coin. The pfennigs were given their contemporary name after their image, a lozenged coat of arms. This pfennig, with its ring of pearls around a central lozenged shield or just a lozenge without a shield, developed into the bowl-shaped Schüsselpfennig in the 15th century. The Weckeler was struck on one side only using a coin die smaller than the actual planchet. The force of the die stamp caused the perimeter of the planchet to curve upwards to a greater or lesser extent. References

Literature 
 Helmut Kahnt: Das große Münzlexikon von A bis Z., Regenstauf 2005
 Heinz Fengler, Gerd Gierow, Willy Unger: transpress Lexikon Numismatik, Berlin 1976
 Friedrich von Schrötter (ed. ), with N. Bauer, K. Regling, A. Suhle, R. Vasmer, J. Wilcke (1970) [reprint of the original 1930 edn.] Wörterbuch der Münzkunde, Berlin: de Gruyter. Silver coins
Coins of the Holy Roman Empire
History of the Palatinate (region)
Pfennig