|Inside of a Talykron shutter|
image by johnnyh4 (Image rights)
Talykron shutters are rim-set leaf shutters made by the Leicester, UK firm of Taylor-Hobson in the 1950s. They are usually seen on folding cameras also equipped with Taylor-Hobson's lenses, often representing the higher level of specification offered in a range.
'Talykron' was also the name of a brand of recording clock (such as might be used to record factory workers' hours worked). These clocks were sold by a Leicester company, 'Talykron Ltd', presumably related to Taylor-Hobson, which was wound up in 1915. 
- An example is held by Museum Victoria in Melbourne, Australia. It was formerly described, without a photograph, in the museum's catalogue listing. See also this catalog entry at the UK National Archives
- The winding-up is announced (half-way down the right-hand column) in this page of The London Gazette (a PDF file of the single page).