Improved Hole Measurements Using Tapered Mandrel Gages
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Disclosed is a method for measuring the diameter of the punched center holes of diskettes more accurately than previous methods. The improved method provides better precision, accuracy, and replication. Prior-art measurement methods involved lowering a diskette with a punched center hole onto a mandrel structured with increasing diameter steps. The test, essentially a "go-no go" type, was undependable because the diskette tended to hang up on the next smaller dimensional step from that it would actually fit over. Additional errors were caused by variations in descent speed of the diskette. The force at which the diskette was applied to the stepped mandrel was proportional to the speed of descent which was manually controlled by the operator. Because of variations in speed, nonpredictable errors were introduced.