Signalling device for navigational purposes or starting sports events - has cylindrical housing containing spiral spring

摘要

The signalling device has a cylindrical housing approximately 10 centimetres long containing the spiral spring which extends along the longitudinal axis of the housing and which is attached to a striker bolt at one end. This bolt has an operating head screwed into it, the shaft of the head passing through a slot, running along the housing, and with a striker for the bolt at the other end of the housing. A point is formed at the end of the striker bolt, which co-operates with a winding device, screwing into an internally threaded sleeve inserted into the open end of the housing.