Timing switch for swimming competitions - has switch operated by swimmer with shaped bridging contact forming spacer between plates

摘要

The switch, mounted at the end of a swimming bath, is used in swimming races, where it is pushed by a swimmer on reaching that end and forms part of the timing system. A back plate (D) made of insulating material, is spaced from a front plate (E) made of a pliable material that will press only the nearest contact when pushed. This is perforated to reduce resistance to movement of the water. On the rear of the outer plate are attached three vertical metal strips (A,B,A) spaced an equal distance apart. Between these strips and the inner plate is a single contact strip or two contact strips spaced some distance apart. Each contact strip is gull wing shaped so that when compressed, its tips bridge the contacts formed by the metal strips. This strip also acts as a spacer between the plates.