Automatic chip removal system for sign engraving machine

A guide member for removing chips generated by a machine using a cutter on a rotating cutting head for engraving a sign blank, the guide member comprising:

• a contact surface forming a circular, flat central face for contacting the sign blank, the contact surface having an access opening at the center thereof for allowing chips to enter the guide member from a cutting region on the sign blank;
• a ramped wall of increasing diameter extending radially from the contact surface and receding from the cutting region, wherein the ramped wall is parallel to an outer envelope of the cutting head;
• a gutter wall having an exhaust opening and located at the periphery of the ramped wall;
• an exhaust chute depending from the guide member at a tangent from the gutter wall for receiving swirling chips that pass through the exhaust opening and exhaust such chips to the exterior of the guide member.

A machine for engraving a sign blank comprising:

• a movable frame;
• a sign support for supporting the sign blank in a support plane that is oriented so that engraving chips fall from a cutting region on the sign blank;
• a cutting head mounted to the movable frame for axial movement along and rotation around a rotation axis that is substantially orthogonal to the support plane;
• the cutter head having a plurality of projecting members with outer edges that taper and recede from the axis of rotation to a periphery of the cutting head;
• wherein the projecting members and the periphery of the cutting head define an envelope as the cutting head rotates;
• and
• a guide member mounted to the frame which is spaced from the envelope, and enclose the envelope and form a chip swirling volume into which chips generated by engraving the sign blank naturally fall, the guide member having
• a contact surface having an access opening through which the cutting tip protrudes to engrave the sign blank,
• a gutter wall having an exhaust opening located slightly beyond the peripheral edge of the face of the cutter head,
• a ramped wall connecting the contact surface to the gutter wall, the ramped wall being parallel to the envelope of the rotating cutting head, and
• an exhaust chute depending from the gutter wall to exhaust chips flowing through the exhaust opening;
• wherein the projecting members rotate when the machine is engraving and deflect chips in the swirling volume so that centrifugal and normal forces cause the chips to swirl, migrate towards the gutter wall, and eventually pass through the exhaust opening in the gutter wall and exhaust through the exhaust chute.

A method for removing chips produced in a machine of the type using a cutter in a rotating cutting head for engaging a sign blank to provide a cutting region on the sign blank, the method comprising:

• orienting an axis of rotation for the cutter closer to horizontal than to vertical relative to a supporting surface for the machine;
• orienting the feed path for the sign blank in an upward direction relative to the supporting surface for the machine;
• propelling the chips through rotation of the cutter head along a helical path within an enclosure which surrounds the cutter and the cutting region, such that the chips are directed into a chute without the use of auxiliary devices such as fans, blowers or vacuum generators;
• and
• exhausting the chips downward toward the supporting surface through the chute along a path that is tangent to the helical path.