Frederick William Collard (1772-1860) and William Frederick Collard (1776-1866) were brothers who made pianos in London, England. By 1799 Frederick William Collard became a a partner with Clementi & Co, then under the name Clementi, Collard, Banger, Hyde & Davis. In 1810 Hyde and Davis retired and William Frederick Collard, already working for the firm, became a partner alongside his brother. After the death of their partner, the famous Muzio Clementi, the firm became known as Collard & Collard, and remained this way until the firm was purchased by Chappell Piano Co. in 1929. The Collard brothers made several patents that improved upon the mechanism of the piano, and in the Great Exhibition of 1851 they won a medal for these improvements.
Literature references:
Clinkscale, M., 1999. Makers of the piano, 1820-1860. Vol. 2, Oxford: Oxford University Press, p.289-290.
Sahlqvist, L., 2013. Clementi & Co 1798–1830: Pianoforte Manufacture in London. pp.1-37.