Measuring instrument

Claim 1

A portable hand-holdable instrument for measurIng linear distance on a surface and providing visible indication of measured distance comprising, a housing having a pair of molded halves, said housing having a top with a window aperture formed therein, a window mounted in the window aperture, said housing having concave opposed ends substantially perpendicular to the top, a wheel counter mounted in said housing adjacent to the window, said counter having a reset button protruding through the top of said housing, said counter having a drive shaft, a molded bevel gear mounted on the drive shaft, a unitary, molded transfer gear member comprising a second bevel gear at one end and a spur gear at the other end and with a disc member of greater diameter than said gears therebetween said transfer gear member being rotatably mounted on a gear shaft formed integral with one of the molded halves of the housing with said second bevel gear meshing with said first bevel gear, a molded drive wheel rotatably mounted in the housing and having a portion of its outer periphery extending beyond said housing, and a second spur gear molded integral with the drive wheel and meshing with the firstmentioned spur gear, said disc member being so dimensioned and positioned as to abut said second spur gear to prevent shifting of said transfer gear member in a direction preventing disengagement of said first and second bevel gears, said drive wheel having its circumference calibrated to the counter to indicate a measured distance for each revolution of the drive wheel, whereby an operator may grip the housing on its concave opposed ends and observe the wheel counter through the top of the housing.