US 4,503,740 AGranted

Optical cutting edge locator for a cutting apparatus

AssigneeCapital Machine Company, Inc.

InventorsRobert D. Brand, Ralph D. Runyan

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Abstract

An optical cutting edge locator for a cutting machine having a knife for cutting single or multiple sheets of material comprises a light source, a light-projecting system above the knife for downwardly projecting a beam of light from the light source along a planar surface of the knife generally perpendicular to the material, thereby to cause a shadow to be cast by the cutting edge of the knife and to create a line between a shadow area and a light area on the material in substantially the same plane as the cutting edge. The light-projecting system includes either a plurality of fiber optic transmission lines having light-emitting ends mounted above the knife or an elongated slot above the knife. The plane of the planar surface of the knife generally bisects either the light-emitting ends of the fiber optic transmission lines or the elongated slot so that the beam of light being downwardly projected is split by the planar surface of the knife.

Claims15

Dependent claims

In a cutting apparatus including a working surface for supporting material to be cut, a movable carriage above the working surface, a knife connected to the carriage, the knife having a downwardly extending planar surface providing a cutting edge in substantially the same plane as the planar surface for cutting through the material in response to movement of the carriage, and optical means for locating the material relative to the cutting edge, the improvement wherein the optical means comprises a light source, at least one light transmission line coupled to the light source, the transmission line including a light-emitting distal end for producing a beam of light, mounting means for mounting the light-emitting end of the transmission line to the carriage above the knife whereby the planar surface of the knife bisects the light-emitting end of the transmission line, and means for blocking substantially one half of the beam of light, the other one half of the beam of light being projected downwardly along the planar surface toward the material, thereby causing the cutting edge to cast a shadow and define a single line between a shadow area and a light area on the material in substantially the same plane as the cutting edge.

Dependencies are inferred from the claim text.