Abstract: The invention is directed to an adaptor device suitable for use with a measuring apparatus to determine the centrality to the centerline of a Woodruff keyway in a shaft. The adaptor allows the measuring apparatus to rest on the top surface or outside diameter of the shaft so that the measuring apparatus can be used to measure the centrality of the side walls to the centerline of the keyway. Accordingly, the measuring apparatus can operate without reference to the bottom of the keyway due to the use of the adaptor of the present invention which is connected to the measuring apparatus. The adaptor can be structured so that it is usable with a measuring apparatus to measure keyways of varying sizes in shafts of varying sizes.

Abstract: A device for measuring the centering, parallelism, and perpendicularity of the side walls of a keyway to the centerline of the keyway in a shaft is described. The preferred embodiment of the device includes a micrometer slidingly attached to the device, a horizontal indicator dial slidingly attached to the device and connected to a horizontally extending probe which is positionable in a shaft keyway, a vertical indicator dial slidingly attached to the device and connected to a vertically extending probe positionable in a shaft keyway, and two stationary legs extending downward from the device for seating in a shaft keyway. In operation, the horizontal indicator dial and horizontal probe are utilized to check the centering and parallelism to the centerline of the keyway and the vertical indicator dial and vertical probe are utilized to check the perpendicularity of the keyway side walls to the centerline of the keyway.