Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 138,035 pages of information and 222,628 images on early companies, their products and the people who designed and built them.
of Odlham, maker of textile machinery
1822 Henry Platt entered a partnership with Elijah Hibbert as Hibbert and Platt and later as Hibbert, Platt and Sons which developed from an assembler of parts manufactured by others, to a fully integrated manufacturer in its own right.
1829–30 Opened Hartford works at Greenacres Moor
1837 John Platt became a partner in the company
1843 'FALL OF A BEAM IN A FOUNDRY.-An alarming and serious accident occurred at the iron foundry of Messrs. Hibbert and Platt, Greenacres Moor, on Thursday evening. The iron beam of one of the foundry roofs gave way, and fell down with a tremendous crash, when several of the workmen were more or less injured by the fall of materials, and one was considered in extreme danger, but is now in course of recovery. It is wonderful that such an affair should have occurred without any loss of life.'
1845 Opened the Hartford new works at Oldham's new railhead
1846 John Platt became the senior partner in the firm after the death of his father in 1842, of his elder brother Joseph (1815–1845), and of Elijah Hibbert in 1846
1851 Employing 1,070 men and 239 boys. 
1851 Award at the 1851 Great Exhibition. See details at 1851 Great Exhibition: Reports of the Juries: Class VI.