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US 4,019,256 AGranted
Guide for tool or instrument
OwnerLance A. Johnsoninventor
Life of this patent
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OwnerLance A. Johnsoninventor
Estimating the term…
A guide to align a cutting or routing tool along a straight line has a stationary support fixed relative to the work and has arm-like linkage between the support and a hand-held tool or instrument. A first end-member of the first parallelogram frame is pivoted to the stationary support, preferably in conjunction with an arcuate angle indicator. Pivoted to this first end-member is a first parallelogram frame consisting of a pair of equal, parallel, arm-members which are pivoted to a pair of tangent identical rollers of a diameter equal to the effective distance between pivot centers of the first end-member. Means, such as bands around the rollers, insure that they revolve in opposite directions the same amount and remain tangent as the first arms move in parallelism. Extending from the center of each roller is one of a second pair of equal, parallel arms of the second frame which are pivoted to a final end-member of the same effective length as the first and the common end-members. The rollers thus constitute an elbow joint for the arm-like device. The final end-member of the second frame is fixed to the tool or to a guide against which the tool or instrument is aligned. One angle of movement of the first arm-members relative to their fixed end results in two angles of movement of the second arm-pair relative to the coupling mechanism. With the first end-member held in constant alignment to the work, movement of the tool or instrument is restricted to a predetermined straight line.
A guide for a tool to be used on a work piece comprising a straight-edge element adapted to be fixed relative to said work piece, an angle-selector plate attached to said element, a first arm, a second arm of equal length to said first arm, first and second pivot means pivotally connecting the first ends of said first and second arms, respectively, to said angle-selector plate, said first and second pivot means being spaced apart a first distance, a first roller mounted in a fixed position on the second end of said first arm, a second roller mounted rotatably on the second end of said second arm, said rollers being of the same diameter, said diameter being equal to said first distance, rotation means to maintain said rollers in tangential contact and to cause said rollers to turn in opposite directions through identical angles, third and fourth arms of equal length and equal to said first and second arms, a first end of said third arm being rotatably connected to said first roller, a first end of said fourth arm being fixed for rotation about the axis of said second roller, and end-member, third and fourth pivot means spaced apart said first distance pivotally connecting the second ends of said third and fourth arms, respectively, to said end-member, and a tool locator fixed relative to said end-member and shaped to receive said tool.
A guide for a tool comprising
Dependencies are inferred from the claim text.