Patent ID: 7726034
Filing Date: 2010-06-01
Classification: B43L,G01B

Abstract:
1. A digital protractor for measuring an angular displacement from a reference surface, which reference surface carries a magnetically attracted material, said protractor comprising: a pair of pivotally interconnected upper and lower arms, which arms are superposable upon one another, each arm having a pair of substantially parallel engagement edges extending longitudinally of said arm, one of said arms being engagable with the reference surface along a selected one of said engagement edges of said arm, each said engagement edge having a channel formed therein for receiving a respective magnetic element that is confined within and does not protrude laterally from said channel, which magnetic element is for adhering to the magnetically attracted material carried by the reference surface when the engagement edge carrying said magnetic element is engaged with the reference surface; an electronic sensor secured to said lower arm; and a digital readout device secured to said upper arm for operatively cooperating with said electronic sensor to measure and display the angular displacement from the arm engaging the reference surface to the other arm.