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US 4,200,987 AGranted
Gauge
OwnerMarvin G. Schmittinventor
Life of this patent
Estimating the term…
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OwnerMarvin G. Schmittinventor
Estimating the term…
A gauge for determining whether a hole is within tolerances is disclosed. Such gauge includes a cylindrical portion proportioned to fit within a hole with a relatively close fit. A paddle is pivotally mounted within the cylindrical portion for rotation in opposite directions from a neutral position. The paddle is formed so that when it is in the neutral position it has end faces which are aligned with the cylindrical portion of the gauge and which fit into the hole with a relatively close fit. One diagonal dimension of the paddle is equal to the minimum diameter of an in-tolerance hole and the other diagonal is equal to the maximum diameter of an in-tolerance hole. Once the gauge is positioned within the hole the paddle is tipped one way to determine if the hole has a diameter at least equal to the minimum diameter of an in-tolerance hole and the other way to determine if the hole has a diameter less than the maximum in-tolerance diameter. The gauge is manufactured by assembling the paddle within the cylindrical portion and grinding the paddle ends and the cylindrical portion to a predetermined diameter smaller than the diameter of the hole to be measured while holding the paddle in a predetermined angular relationship to a plane perpendicular to the axis of the cylindrical portion.
A gauge comprising a support providing a cylindrical surface having a first axis, said cylindrical surface having a first diameter a sufficient amount smaller than the diameter of hole to be measured to permit easy insertion of said cylindrical surface into said hole, a paddle journaled on said support for pivotal movement about a second axis substantially perpendicular to said first axis and providing oppositely extending extensions, each extension providing an end face aligned with said cylindrical surface when said paddle is in a first position, said paddle providing a first diagonal having a length equal to the minimum diameter of a hole to be measured and a second diagonal equal to the maximum diameter of a hole to be measured, and operator means operable to pivot said paddle around said second axis while said paddle and cylindrical surface are in a hole to be measured from said first position toward a second position in which said first diagonal is perpendicular to said first axis and toward a third position in which said second diagonal is perpendicular to said first axis.
A method of manufacturing gauges for measuring a diameter of holes comprising assembling a paddle within a cylindrical portion of a support with said paddle mounted for pivotal movement about an axis perpendicular to and intersecting the axis of said cylindrical portion, providing said paddle with opposite extensions having ends substantially flush with the surface of said cylindrical portion, and while holding said paddle at a predetermined mid-position having a predetermined angle with respect to a plane perpendicular to the axis of said cylindrical portion simultaneously grinding said cylindrical portion and said ends of said paddle to a predetermined diameter smaller than the minimum diameter of a hole to be measured, the height of said ends of said paddle and said angle being selected so that said grinding produces a first paddle diagonal equal to the minimum diameter of a hole to be measured and a second paddle diagonal equal to the maximum diameter of a hole to be measured.
Dependencies are inferred from the claim text.