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.

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.