US Patent 7574815 Wheeled distance measuring device

A wheeled distance measuring device includes a housing attached to a pole, a counter attached to the housing and having a spindle extended out of the housing, and two gear members of different diameters selectively attached to the spindle, a wheel including a wheel axle attached to the housing, a carrier adjustably attached to the housing, a gear element rotatably attached to the carrier for selectively engaging with either of the gear members, and a gear coupling mechanism coupled between the wheel axle and the gear element for allowing the gear element to be rotated by the wheel axle to rotate either of the gear members and for forming either a metric or a British scale or unit or system.