Patent ID: 7640676
Filing Date: 2010-01-05
Classification: B27B,G05B,Y10T

Abstract:
1. A distance measuring device for use with a power tool having a base, an alignment fence, and an alignment area defined by the power tool base and the power tool alignment fence for receiving a work piece, said distance measuring device comprising: a first electronic rotary encoder having an input shaft, said first electronic rotary encoder being proximate to the alignment area and producing a first output signal that corresponds to a longitudinal motion of the work piece within the alignment area when an outer surface of the work piece simultaneously slidably engages the power tool base and the power tool alignment fence, wherein said first output signal corresponds to the rotation of said first electronic rotary encoder input shaft; a first distance measuring wheel fixed on said first electronic rotary encoder input shaft and having an outer circumferential surface in rolling engagement with an outer surface of the work piece; a second electronic rotary encoder having an input shaft, said second electronic rotary encoder being proximate to the alignment area and producing a second output signal that corresponds to a longitudinal motion of the work piece within the alignment area when an outer surface of the work piece simultaneously slidably engages the power tool base and the power tool alignment fence, wherein said second output signal corresponds to the rotation of said second electronic rotary encoder input shaft; a second distance measuring wheel fixed on said second electronic rotary encoder input shaft and having an outer circumferential surface in rolling engagement with an outer surface of the work piece; a first support bracket; a second support bracket; a first arm having a first end rigidly attached to said first electronic rotary encoder and a second end pivotally attached to said first support bracket; a second arm having a first end rigidly attached to said second electronic rotary encoder and a second end pivotally attached to said second support bracket; a processor that receives said first and second output signals, determines a longitudinal distance traveled by said work piece within the alignment area from said first and second output signals, and outputs a third signal that corresponds to the longitudinal distance traveled by the work piece within the alignment area; and an electronic digital display receiving said third signal from said processor and providing an alpha-numeric representation of the distance traveled by the work piece within the alignment area; wherein the power tool alignment fence comprises: wherein said first support bracket is rigidly attached to a rear surface of the first alignment fence section and disposed such that said first arm first end extends so as to locate said first measuring wheel between the power tool alignment fence first section and the power tool alignment fence second section; and wherein said second support bracket is rigidly attached to a rear surface of the fourth alignment fence section and disposed such that said second arm first end extends so as to locate said second measuring wheel between the power tool alignment fence third section and the power tool alignment fence fourth section.