This is an early roller-blind shutter, the blind is wound to the top roller in the shutter by a cogwheel, when released the blind is pulled by a spring in the lower roller, the spring tension can be varied by a ratchet and pawl mechanism. The basic design was copied by many manufacturers especially Thornton-Pickard.

The shutter was improved in 1890 by the addition of a Time setting.

John Kershaw, the patentee of the shutter, was a photographer operating studios in Buxton. It is not certain that the shutter was manufactured by the Kershaw family but given that the two sons of John Kershaw describe themselves in the census as shutter manufacturers it seems probable that this was a sideline carried out along with their studio business. J.T. Chapman advertised the shutter in 1886. Not many shutters could have been produced as they are not often seen today.

This is a roller-blind shutter with the unusual feature of being regulated by a pneumatic delay. The upper spindle has attached to it a pinion, this works within a rack the bottom of which is connected to the piston of the delay cylinder.

The early models showed the speeds on a quadrant-shaped scale, later an arm along the lower edge of the shutter was used.

The shutter is robust and works well. It was not given much emphasis in N&G advertisements and did not sell in large numbers.

This patent included the use of a worm wheel to display the speeds. The mechanism is an improvement on Kershaw's earlier roller-blind patents.