Abstract: A computer controlled laser machine tool is provided wherein the machine tool work zone is smaller than the size of the workpiece that can be processed. The machine tool has an apparatus to register the workhead guidance system to the workpiece without requiring a hole in the workpiece. The machine tool is adapted with an image sensor, a form of a digital camera, to measure the position of targets etched in or affixed to the surface of the workpiece. Registration of the workhead guidance system relative to the workpiece is checked before and after the workpiece support is indexed.

Abstract: A computer controlled laser machine tool is provided wherein the machine tool work zone is smaller than the size of the workpiece that can be processed. The machine tool has an apparatus to register the workhead guidance system to the workpiece without requiring a hole in the workpiece. The machine tool is adapted with an image sensor, a form of a digital camera, to measure the position of targets etched in or affixed to the surface of the workpiece. Registration of the workhead guidance system relative to the workpiece is checked before and after the workpiece support is indexed.

Abstract: A controller for laser piercing and cutting metal sheet and plate comprising a computer readable file displayable on a human machine interface display screen of a laser equipped CNC machine tool, communicating with a part program for processing a workpiece, adapted with a plurality of setup data and parameters for piercing and cutting a type and thickness of material, adapted substantially as a table, the table comprising a plurality of parameters, each parameter controlling a unique function of operation and comprising a plurality of steps comprised of a first setup step and a plurality of variable time increment steps, each variable time increment step controlling a portion of the pierce cycle and the table associated with a plurality of parameters controlling cutting the workpiece.

Abstract: A controller for laser piercing and cutting metal sheet and plate comprising a computer readable file displayable on a human machine interface display screen of a laser equipped CNC machine tool, communicating with a part program for processing a workpiece, adapted with a plurality of setup data and parameters for piercing and cutting a type and thickness of material, adapted substantially as a table, the table comprising a plurality of parameters, each parameter controlling a unique function of operation and comprising a plurality of steps comprised of a first setup step and a plurality of variable time increment steps, each variable time increment step controlling a portion of the pierce cycle and the table associated with a plurality of parameters controlling cutting the workpiece.

Abstract: A machine tool loading apparatus is adapted to register the sheets being loaded directly in the workclamps of the machine tool. A four bar linkage is utilized to control the position of the sheet as the loader removes it from the supply stack and brings it into the workclamps. The four bar linkage is provided with a controlled amount of compliance which is released as the sheet is brought into the workclamps. The sheet is thus allowed a limited ability to be repositioned as the loading mechanism guides it into the workclamps, so that a registered position is achieved before the workclamps are closed. The preferred loader apparatus can be used to unload large parts from the machine tool. The loader apparatus may be adapted to the machine tool in conjunction with a material storage tower.

Abstract: A cube corner laser beam retroreflector apparatus for a beam path external to a laser reduces the effect of small deviations in flatness of optical carriage mounting elements and/or linear ways that pitch, yaw and roll the carried retroreflector apparatus. Small changes in pitch, yaw and roll are converted to a small translation in position of the beam reflected from the apparatus. Since the reflected beam remains parallel to the incoming beam, the length of the beam path does not magnify such small deviations in position and system pointing stability is greatly improved. The cube corner retroreflector comprises a welded frame and three mirror holders, the welded frame consisting of plasma, laser or abrasive water jet cut tabbed and slotted flat plates welded together. Each mirror holder is adjustably attached to the welded frame and houses a removable mirror.

Abstract: A laser beam position control apparatus for a CNC laser equipped machine tool, that will automatically maintain precise alignment of the beam path, though the machine may be operating in a non-uniform temperature environment. The apparatus compensates for small deviations in flatness of machine mounting surfaces by steering the laser beam. The laser beam control apparatus includes a laser beam position sensor for mounting in the beam path of the machine tool and that communicates with a signal processor that in turn communicates with at least one drive apparatus that controls at least one actuator capable of moving an object to steer the laser beam.

Abstract: A machine tool loading apparatus is adapted to register the sheets being loaded directly in the workclamps of the machine tool. A four bar linkage is utilized to control the position of the sheet as the loader removes it from the supply stack and brings it into the workclamps. The four bar linkage is provided with a controlled amount of compliance which is released as the sheet is brought into the workclamps. The sheet is thus allowed a limited ability to be repositioned as the loading mechanism guides it into the workclamps, so that a registered position is achieved before the workclamps are closed. The preferred loader apparatus can be used to unload large parts from the machine tool. The loader apparatus may be adapted to the machine tool in conjunction with a material storage tower.

Abstract: A cube corner laser beam retroreflector apparatus for a beam path external to a laser reduces the effect of small deviations in flatness of optical carriage mounting elements and/or linear ways that pitch, yaw and roll the carried retroreflector apparatus. Small changes in pitch, yaw and roll are converted to a small translation in position of the beam reflected from the apparatus. Since the reflected beam remains parallel to the incoming beam, the length of the beam path does not magnify such small deviations in position and system pointing stability is greatly improved. The cube corner retroreflector comprises a welded frame and three mirror holders, the welded frame consisting of plasma, laser or abrasive water jet cut tabbed and slotted flat plates welded together. Each mirror holder is adjustably attached to the welded frame and houses a removable mirror.

Abstract: A heavy-duty laser plate cutting machine capable of cutting heavy plate but which can also operate on lighter sheet metal at commercial production rates. The machine includes a laser source having an output power of 3 kilowatts or more. The machine is preferably of the flying optic configuration, and an automatic beam control system is interposed between the laser source and a focusing optic carried in the cutting head. The cutting head, in addition to normal z axis control, has an adjustment to position the focal spot relative to the workpiece. The focal spot can be driven into the workpiece when cutting heavy plate. The cutting head is configured to carry focusing optics having different focal lengths, such as those suitable for thick plate and thin sheet. The x and y axes include linear motors to precisely traverse the bridge and cutting head along the axes at speeds suitable for heavy plate, and at higher speeds suitable for thinner sheet.

Abstract: A control system is provided for a laser-equipped machine tool which is capable of preventing self-burning. The temperature of the workpiece proximate the cut is monitored, and a numerical control compares the actual workpiece temperature to a prestored temperature limit, empirically determined, which is predictive of the onset of self-burning. If the workpiece temperature approaches or reaches the limit, an abort signal is generated. Upon generation of an abort signal the control processor deenergizes the laser to prevent commencement of self-burning. In addition the processor stores the cutting parameters and the coordinate locations of the aborted cut, so that the processor can later return to finish the cut, and sets a cool-down timer. The processor then causes movement to a next available cutting position, tests the temperature at that position, then commences cutting.

Abstract: An insulated slag collection bed and scrap removal system for a high powered laser-equipped machine tool. The slag collection bed serves as a shield to absorb remnant laser energy which would otherwise strike the machine base. The shield is thermally insulated from the machine base so as to protect the machine base from the temperature rise in the shield resulting from absorbing the remnant laser energy. If, over time the shield is damaged or worn, apparatus is provided for ready replacement of both the shield and the insulation. The scrap removal system has a home position in which all of its components, including a scraper assembly and a drive are out of the range of the laser beam, so that they are protected from laser damage. The drive is energized to pull a scraper assembly through the machine with a plow having a lower surface in contact with the stationary collection bed for scraping slag and pushing it toward the open end of the machine.

Abstract: A laser beam position control apparatus for a CNC laser equipped machine tool, that will automatically maintain precise alignment of the beam path, though the machine may be operating in a non-uniform temperature environment. The apparatus compensates for small deviations in flatness of machine mounting surfaces by steering the laser beam. The laser beam control apparatus includes a laser beam position sensor for mounting in the beam path of the machine tool and that communicates with a signal processor that in turn communicates with at least one drive apparatus that controls at least one actuator capable of moving an object to steer the laser beam.

Abstract: A heavy-duty laser plate cutting machine capable of cutting heavy plate at production rates. The machine includes a laser source having an output power of 4 kilowatts or more. The machine is preferably of the flying optic configuration, and an automatic beam control system, such as an automatically adjustable collimator is interposed between the laser source and a focusing optic carried in the cutting head. The cutting head, in addition to normal Z-axis control, has an adjustment to position the focal spot relative to the workpiece. The focal spot can be driven into the workpiece when cutting heavy plate. A machine bed underlying the workpiece is capable of absorbing significant energy from the remnant laser beam without damaging the machine base.

Abstract: A method and apparatus for real time control of laser beam characteristics in a high power laser-equipped machine tool. A beam path input signal is produced related to changes in the length of the laser beam path as the processing head of the machine tool moves over the workpiece. An integrator produces a signal related to the real time changes in thermal loading of the laser output coupler as the laser beam is applied and as the output power level is adjusted. The beam path and thermal loading signals are used to drive a collimator so as to correct in real time for altered beam characteristics introduced by path length changes and thermal lensing of the output coupler. The result is to maintain control of the beam size at the focus optic. In addition, a further integrator produces a signal related to the real time changes in thermal loading of the focal optic as the laser beam is applied and as the input laser power level is adjusted.

Abstract: An insulated slag collection bed for a laser-equipped machine tool. The bed substantially insulates the machine tool base from thermal damage due to the laser beam of the machine tool. Typically the laser beam in a machine tool will have significant energy density in planes below the workpiece, and in some conditions the energy density will be sufficient to damage the machine base. The present invention protects the machine base by providing a slag collection bed which serves as a shield to absorb remnant laser energy which would otherwise strike the machine base. The shield is thermally insulated from the machine base so as to protect the machine base from the temperature rise in the shield resulting from absorbing the remnant laser energy. If, over time the shield is damaged or worn, means are provided for ready replacement of both the shield and the insulation.

Abstract: An air handling system for a laser-equipped machine tool. The machine base is specially configured to include and form part of the duct work which extracts fumes produced during the cutting operation. An elongated collection duct is provided in portions of the machine base bracketing a slag collection surface, and the port pattern in the collection ducts is graduated so as to achieve relatively even flow across the entire machine. The collection duct communicates with a main duct in the machine base which has outlet connections at three sides of the base, affording flexibility in selecting a particular outlet for connection to an external vacuum source. Cooperating with the air extraction components, the machine is enclosed and air vents are provided at strategic locations in the enclosure to control both the volume and direction of air into the enclosure to provide for efficient extraction of fumes produced as a by-product of the cutting operation.

Abstract: A cutting head for a laser-equipped machine tool in which the cutting head has a controllably positionable optic carrier for adjusting the position of the beam focus. The focusing optic has a reaction force imposed on it by the assist gas coupled to the cutting nozzle. The magnitude of the force varies with the pressure of the assist gas, and can be very substantial. A counterbalance mechanism connected between the cutting head and the optic carrier is operated from the same assist gas source which supplies the nozzle, and creates a force on the optic in the opposite direction of the reaction force and which has a magnitude which closely compensates it. The system also provides for rapid purge of assist gas when switching from one type of assist gas to another.

Abstract: A scrap removal system for a laser-equipped machine tool. The scrap removal system has a home position in which all of its components, including a scraper assembly and a drive are out of the range of the laser beam, so that they are protected from laser damage. A stationary slag and scrap collection bed is provided below the cutting zone. The scrap removal system is periodically activated, at times when the laser is off. The drive has drive components which span the length of the bed out of the path of the laser. The drive is energized to pull a scraper assembly through the machine with a plow having a lower surface in contact with the stationary collection bed for scraping slag and pushing it toward the open end of the machine.

Abstract: A reflective collimator for a laser, such as for use in a cutting or welding machine tool. The collimator requires no more than three mirrors, and can be configured with only two. The relative positions of a convex/concave mirror pair are adjusted to adjust the divergence of the output collimated beam. Adjustment is accomplished by translating two of the mirrors in linear paths along respective beam paths established in the collimator. A linkage interconnects the two translatable mirrors and includes a coupling which incorporates the triangular geometry of the beam path established by the mirrors, so that the translatable mirrors are linked to maintain alignment throughout the range of collimator adjustment. When one of the translatable mirrors is adjusted the linkage causes the second to track the first while maintaining precise alignment in the collimator.