DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0048] Reducing the disruptive aspects of material processing has long been a goal of those in materials processing industries, particularly in industries that require materials processing within or near occupied structures, such as is common in renovation and many other applications. Such long-felt needs have been particularly prevalent in seismically active areas of the earth, where there is a pressing need for an effective and economical means of retrofitting occupied structures to increase the safety of these structures.

[0049] Prior technologies are plagued by disruptive characteristics, thereby making them virtually unsuitable for retrofitting occupied structures. Additionally, such material processing technologies often present dangerous and costly “cut through” dangers. “Cut through” dangers include instances such as a worker unintentionally cutting an embedded object while drilling through the subject material. For example, a construction worker drilling a hole in an existing concrete wall may accidentally encounter reinforcing steel or rebar, or embedded utilities, such as live electrical conduit and conductors. Such an incident may result in costly damage to tools or the subject material, as well as potentially deadly consequences (e.g., electrocution) for workers. Traditional drilling methods also can include “punch through” dangers of unexpectedly punching through the material drilled and damaging structures or personnel on the opposite side of the material.

[0050] In addition, traditional material processing equipment has been extremely burdensome to operate. Handheld power drilling and hammering devices commonly weigh in excess of fifty pounds and are often required to be held overhead by the operator for extended period of time. Conventional devices also typically produce jarring forces that the operator must absorb while holding the device. Besides the potentially injurious jarring forces, sustained heavy lifting, and “cut through” dangers, the operator and those in the vicinity of the device may be exposed to falling or projectile debris, as well as dust, fumes, vapors, vibration, and noise. This level of noisome activity is unsuitable in general for occupied structures, and is entirely unsuitable for structures used as hospitals, laboratories, and the like, where noise and vibration can be completely unacceptable.

[0051] What continues to be needed but missing from this field of art is a non-disruptive material processing technology that overcomes the drawbacks illustrated above. In certain embodiments described herein, energy waves are directed toward the surface to be processed to overcome some or all of such drawbacks. The energy waves of certain embodiments are electromagnetic waves (e.g., laser light, microwaves), while in other embodiments, they are acoustic waves (e.g., ultrasonic waves). However, in certain embodiments, such cutting units can be as bulky and often are as difficult to maneuver as their mechanical counterparts. In addition, lasers can be subject to the same “cut through” dangers as described above, wherein objects hidden within the matrix of the material to be processed can be inadvertently damaged. Lasers can also pose additional dangers of “punch through” with danger to persons or objects in the path of the laser beam. Lasers can also present complexities in removing drilled material from a cut or a drilled hole. In certain embodiments, the laser system would incorporate a remote laser generator communicating with a portable processing head that incorporates numerous non-disruptive and safety features allowing the system to be utilized within or near occupied structures.

[0052] Certain embodiments of the present invention provide fast material processing while addressing many of the shortcomings of prior technologies and allowing for heretofore unavailable benefits (e.g., reduced disruption to activities within the structure). In certain embodiments, the method and apparatus utilize fiber connections between elements such that noisy, bulky, and heavy elements can operate at a significant distance from the actual work area. Certain embodiments are low in both noise and vibration during operation, and effectively remove dust and debris. Certain embodiments include a detection system to reduce the dangers of “cut through” or “punch through.” Certain embodiments enhance worker safety by allowing workers to be located away from the work area during material processing. Certain embodiments are separable into man-portable pieces (e.g., less than 50 pounds) to facilitate transportation to locations in proximity to or within the structure being processed by providing easy and fast portability and set-up.

[0053] Certain embodiments of the present invention provide a method and apparatus for processing fragile structures which may be damaged by conventional processing techniques. For example, using conventional saws for processing concrete grain silos as part of a retrofit or refurbishment process may result in vibrations damaging to other portions of the silo. Using a laser to process the fragile structure can reduce the collateral damage done to the structure during processing. Furthermore, certain embodiments described herein are easily assembled/disassembled, so they can be used in otherwise inaccessible portions of the structures. While embodiments described herein are disclosed in terms of processing man-made structures, in still other embodiments, the present invention can be useful for processing natural formations (e.g., as part of a mining or drilling operation).

[0054] The method and apparatus described herein represent a significant advance in the state of the art. Various embodiments of the apparatus comprise new and novel arrangements of elements and methods that are configured in unique and novel ways and which demonstrate previously unavailable but desirable capabilities. In particular, certain embodiments of the present invention provide a material processing method that is quiet, substantially vibration-free, and less likely to exude dust, debris, or noxious fumes. Additionally, certain embodiments allow a higher rate of material processing than do conventional technologies.

[0055] The detailed description set forth below in connection with the drawings is intended merely as a description of various embodiments of the present invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth illustrated embodiments of the designs, functions, apparatus, and methods of implementing the invention. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.

[0056] FIG. 1 schematically illustrates an embodiment of an apparatus 50 for processing a structure having a surface. The apparatus 50 comprises a laser base unit 300 , a laser manipulation system 100 , and a controller 500 . The laser base unit 300 is adapted to provide laser light to an interaction region and includes a laser generator 310 and a laser head 200 coupled to the laser generator 310 . The laser head 200 is adapted to remove the material from the interaction region. The laser manipulation system 100 includes an anchoring mechanism 110 adapted to be releasably coupled to the structure and a positioning mechanism 121 coupled to the anchoring mechanism 110 and coupled to the laser head 200 . The laser manipulation system 100 is adapted to controllably adjust the position of the laser head 200 relative to the structure. The controller 500 is electrically coupled to the laser base unit 300 and the laser manipulation system 100 . The controller 500 is adapted to transmit control signals to the laser base unit 300 and to the laser manipulation system 100 in response to user input.

[0057] In certain embodiments, the laser head 200 is releasably coupled to the laser generator 310 and is releasably coupled to the positioning mechanism 121 . In certain embodiments, the positioning mechanism 121 is releasably coupled to the anchoring mechanism 110 , and the controller 500 is releasably coupled to the laser base unit 300 and the laser manipulation system 100 . Such embodiments can provide an apparatus 50 which can be reversibly assembled and disassembled to facilitate transportation of the apparatus 50 to locations in proximity to or within the structure being processed.

[0058] Laser Base Unit

[0059] Certain embodiments of the laser base unit 300 are described below. While the laser base unit 300 is described below as comprising separate components, other embodiments can include combinations of two or more of these components in an integral unit.

[0060] Laser Generator

[0061] FIG. 2 schematically illustrates a laser base unit 300 compatible with embodiments described herein. In certain embodiments, the laser base unit 300 comprises a laser generator 310 and a cooling subsystem 320 . The laser generator 310 is coupled to a power source (not shown) which provides electrical power of appropriate voltage, phase, and amperage sufficient to power the laser generator 310 . The power source can also be portable in certain embodiments, and can operate without cooling water, air, or power from the facility at which the apparatus 50 is operating. Exemplary power sources include, but are not limited to, diesel-powered electric generators.

[0062] In certain embodiments, the laser generator 310 preferably comprises an arc-lamp-pumped Nd:YAG laser, but may alternatively comprise a CO ₂ laser, a diode laser, a diode-pumped Nd:YAG laser, a fiber laser, or other types of laser systems. The laser generator 310 can be operated in either a pulsed mode or a continuous-wave mode. One exemplary laser generator 310 in accordance with embodiments described herein includes a Trumpf 4006D, 4000-watt, continuous-wave laser available from Trumpf Lasertechnik GmbH of Ditzingen, Germany. In other exemplary embodiments, a Yb-doped fiber laser or an Er-doped fiber laser can be used. Other types of lasers with other power outputs (e.g., 2000-watt) are compatible with embodiments described herein. Depending on the requirements unique to a given application of the method and apparatus described herein, one skilled in the art will be able to select the optimal laser for the purposes at hand.

[0063] In certain embodiments, the laser generator 310 can be located within a shipping container for ease of transport and storage. The laser generator 310 generates laser light which is preferably delivered through a glass fiber-optic cable from the laser generator 310 to the work location.

[0064] In certain alternative embodiments, the laser generator 310 comprises a gas-based CO ₂ laser which generates laser light by the excitation of CO ₂ gas. Such lasers provide high power output (e.g., ˜100 W-50 kW) at high efficiencies (e.g., ˜5-13%), and are relatively inexpensive. The laser light generated by such gas-based CO ₂ lasers is typically delivered by mirrors and by using a system of ducts or arms to deliver the laser light around bends or corners.

[0065] In certain alternative embodiments, the laser generator 310 comprises a diode laser. Such diode lasers are compact compared to gas and Nd:YAG lasers so they can be used in a direct delivery configuration (e.g., in close proximity to the work site). Diode lasers provide high power (e.g., ˜10 W-6 kW) at high power efficiencies (e.g., ˜25-40%). In certain embodiments, the laser light from a diode laser can be delivered via optical fiber, but with some corresponding losses of power.

[0066] Embodiments using a Nd:YAG laser can have certain advantages over embodiments with CO ₂ lasers or diode lasers. There is long industrial experience with Nd:YAG lasers in the materials processing industry and they provide high power (e.g., ˜100 W-6 kW). Additionally, the laser light from a Nd:YAG laser can be delivered by optical fiber with only slight power losses (e.g., ˜12%) through a relatively small and long optical fiber. This permits the staging of the laser generator 310 and support equipment in locations relatively far (e.g., about 100 meters) from the work area. Maintaining the laser generator 310 at a distance from the surface being processed allows the remainder of the apparatus 50 to be smaller and more portable.

[0067] Arc-lamp-pumped Nd:YAG lasers use an arc lamp to excite a Nd:YAG crystal to generate laser light. Diode-pumped Nd:YAG lasers use diode lasers to excite the Nd:YAG crystal, resulting in an increase in power efficiency (e.g., ˜10-25%, as compared to less than 5% for arc-lamp-pumped Nd:YAG lasers). This increased efficiency results in the diode-pumped laser having a better beam quality, and requiring a smaller cooling subsystem 320 . An exemplary arc-lamp-pumped Nd:YAG laser is available from Trumpf Lasertechnik GmbH of Ditzingen, Germany.

[0068] Nd:YAG and other solid state lasers (e.g., Nd:YLiF ₄ , Ti:Sapphire, Yb:YAG, etc.) compatible with embodiments described herein can be configured and pumped by a number of methods. These methods include, but are not limited to, flash and arc lamps, as well as diode lasers. Various configurations of the solid state media are compatible with embodiments described herein, including, but not limited to, rod, slab, and disk configurations. The advantages of the different configurations and pumping methods will impact various aspects of the laser generator 310 , including, but not limited to, the efficiency, the beam quality, and the operational mode of the laser generator 310 . An exemplary diode-laser-pumped Nd:YAG disk laser is available from Trumpf Lasertechnik GmbH of Ditzingen, Germany.

[0069] Fiber lasers use a doped (e.g., doped with ytterbium or erbium) fiber to produce a laser beam. The doped fiber can be pumped by other light sources including, but not limited to, arc lamps and diodes. The fiber laser can be coupled into a delivery fiber which carries the laser beam to the interaction location. In certain embodiments, a fiber laser provides an advantageous efficiency of approximately 15% to approximately 20%. Such high efficiencies make the laser generator 310 more mobile, since they utilize smaller chiller units. In addition, such high efficiency laser generators 310 can be located closer to the processing area. An exemplary fiber laser compatible with embodiments described herein is available from IPG Photonics of Oxford, Mass.

[0070] Typically, the generation of laser light by the laser generator 310 creates excess heat which is preferably removed from the laser generator 310 by the cooling subsystem 320 coupled to the laser generator 310 . The amount of cooling needed is determined by the size and type of laser used, but can be about 190 kW of cooling capacity for a 4-kW Nd:YAG laser. The cooling subsystem 320 can utilize excess cooling capability at a job site, such as an existing process water or chilled water cooling subsystem. Alternatively, a unitary cooling subsystem 320 dedicated to the laser generator 310 is preferably used. Unitary cooling subsystems 320 may be air- or liquid-cooled.

[0071] In certain embodiments, as schematically illustrated in FIG. 2 , the cooling subsystem 320 comprises a heat exchanger 322 and a water chiller 324 coupled to the laser 310 to provide sufficient circulatory cooling water to the laser generator 310 to remove the excess heat. The heat exchanger 322 preferably removes a portion of the excess heat from the water, and circulates the water back to the water chiller 324 . The water chiller 324 cools the water to a predetermined temperature and returns the cooling water to the laser generator 310 . Exemplary heat exchangers 322 and water coolers 324 in accordance with embodiments described herein are available from Trumpf Lasertechnik GmbH of Ditzingen, Germany.

[0072] Laser Head

[0073] In certain embodiments, the laser head 200 is coupled to the laser generator 310 and serves as the interface between the apparatus 50 and the structure being irradiated. As schematically illustrated by FIG. 1 , an energy conduit 400 couples the laser head 200 and the laser generator 310 and facilitates the transmission of energy from the laser generator 310 to the laser head 200 . In certain embodiments, the energy conduit 400 comprises an optical fiber which transmits laser light from the laser generator 310 to the laser head 200 . In other embodiments, the energy conduit 400 comprises conductors that may include fiber-optic, power, or control wiring cables.

[0074] FIG. 3A schematically illustrates a laser head 200 in accordance with embodiments described herein. The laser head 200 comprises a connector 210 , at least one optical element 220 , a housing 230 , and a containment plenum 240 . In certain embodiments, the connector 210 is coupled to the housing 230 , is optically coupled to the laser generator 310 via the energy conduit 400 , and is adapted to transmit laser light from the laser generator 310 . The optical element 220 can be located within the connector 210 , the housing 230 , or the containment plenum. 240 . FIG. 3A illustrates an embodiment in which the optical element 220 is within the housing 230 . In embodiments in which the conduit 400 provides laser light to the laser head 200 , the laser light is transmitted through the optical element 220 prior to impinging on the structure being irradiated.

[0075] Laser Head: Extended Configuration

[0076] FIG. 3B schematically illustrates one configuration of a laser head 200 in accordance with embodiments described herein. The housing 230 comprises a distal portion 232 , an angle portion 234 , and a proximal portion 236 . As used herein, the terms “distal” and “proximal” have their standard definitions, referring generally to the position of the portion relative to the interaction region. The connector 210 is coupled to the distal portion 232 , which is coupled to the angle portion 234 , which is coupled to the proximal portion 236 , which is coupled to the containment plenum 240 . Configurations such as that illustrated by FIG. 3B can be used for drilling and scabbling the surface of the structure (e.g., concrete wall). Various components of the laser head 200 are available from Laser Mechanisms, Inc. of Farmington Hills, Mich.

[0077] In certain embodiments in which the energy conduit 400 comprises an optical fiber, the connector 210 receives laser light transmitted from the laser generator 310 through the optical fiber to the laser head 200 . In certain such embodiments, the connector 210 comprises a lens 212 which collimates the diverging laser light emitted by the conduit 400 . The lens 212 can comprise various materials which are transmissive and will refract the laser light in a desired amount. Such materials include, but are not limited to, borosilicate crown glass (BK7), quartz (SiO ₂ ), zinc selenide (ZnSe), and sodium chloride (NaCl). The material of the lens 212 can be selected based on the quality, cost, and stability of the material. Borosilicate crown glass is commonly used for transmissive optics with Nd:YAG lasers, and zinc selenide is commonly used for transmissive optics with CO ₂ lasers.

[0078] The lens 212 can be mounted in a removable assembly in certain embodiments to facilitate cleaning, maintenance, and replacement of the lens 212 . In addition, the mounting of the lens 212 can be adjustable (e.g., using thumbscrews or Allen hex screws) so as to optimize the alignment and focus of the light beam. In certain embodiments, the lens 212 can provide additional modification of the beam profile (e.g., focussing, beam shape).

[0079] The collimated laser light of certain embodiments is then transmitted through the laser head 200 via other optical elements within the laser head 200 . In certain embodiments, the distal portion 232 comprises a generally straight first tube through which laser light propagates to the angle portion 234 , and the proximal portion 236 comprises a generally straight second tube through which the laser light from the angle portion 234 propagates. In certain embodiments, the distal portion 232 contains a lens 233 , and the angle portion 234 contains a mirror 235 which directs the light through the proximal portion 236 and the containment plenum 240 onto the structure. In other embodiments, other devices (e.g., a prism) can be used in the angle portion 234 to direct the light through the proximal portion 236 and the containment plenum 240 onto the structure.

[0080] The lens 233 can be mounted in a removable assembly in certain embodiments to facilitate cleaning, maintenance, and replacement of the lens 233 . In addition, the mounting of the lens 233 can be adjustable (e.g., using thumbscrews or Allen hex screws) so as to optimize the alignment and focus of the light beam. In certain embodiments, the lens 233 focuses the light received from the lens 212 , while in other embodiments, the lens 233 can provide additional modification of the beam profile (e.g., beam shape). Exemplary lenses 233 include, but are not limited to, a 600-mm focal length silica plano-convex lens (e.g., Part No. PLCX-50.8-309.1-UV-1064 available from CVI Laser Corp. of Albuquerque, N.M.). The lens 233 can comprise various materials which are transmissive and will refract the laser light in a desired amount. Such materials include, but are not limited to, borosilicate crown glass, quartz, zinc selenide, and sodium chloride. Exemplary lens mounting assemblies include, but are not limited to, Part Nos. PLALH0097 and PLFLH0119 available from Laser Mechanisms, Inc. of Farmington Hills, Mich.

[0081] In the embodiment schematically illustrated by FIG. 3B in which the distal portion 232 is substantially perpendicular to the proximal portion 236 , the mirror 235 reflects the light through an angle of approximately 90 degrees. Other embodiments are configured to reflect the light through other angles. The mirror 235 can be mounted on a removable assembly in certain embodiments to facilitate cleaning, maintenance, and replacement of the mirror 235 . In addition, the mounting of the mirror 235 can be adjustable (e.g., using thumbscrews or Allen hex screws) so as to optimize the alignment and focus of the light beam. In certain embodiments, the mirror 235 can also have a curvature or otherwise be configured so as to focus the light beam or otherwise modify the beam profile (e.g., beam shape). Exemplary mirrors 235 include, but are not limited to, metal mirrors such as copper mirrors (e.g., Part Nos. PLTRG19 and PLTRC0024 from Laser Mechanisms, Inc. of Farmington Hills, Mich.), and gold-coated copper mirrors (e.g., Part No. PLTRC0100 from Laser Mechanisms, Inc.). In other embodiments, dielectric-coated mirrors can be used.

[0082] FIG. 3C schematically illustrates another configuration of a laser head 200 in accordance with embodiments described herein. The housing 230 comprises the distal portion 232 , a first angle portion 234 , a second angle portion 234 ′, and the proximal portion 236 . The connector 210 is coupled to the distal portion 232 , which is coupled to the first angle portion 234 , which is coupled to the second angle portion 234 ′, which is coupled to the proximal portion 236 , which is coupled to the containment plenum 240 . Configurations such as that illustrated by FIG. 3C can be used for cutting the structure in spatially constrained regions (e.g., cutting off portions of a concrete wall near a corner or protrusion).

[0083] As described above, in certain embodiments, the connector 210 comprises a lens 212 and the distal portion 232 is tubular and contains a lens 233 . The first angle portion 234 of the embodiment illustrated by FIG. 3C contains a first mirror 235 which directs the light to the second angle portion 234 ′ which contains a second mirror 235 ′. The second mirror 235 ′ directs the light through the proximal portion 236 , which can be tubular, and through the containment plenum 240 onto the structure. In certain embodiments, as described more fully below with respect to the containment plenum 240 , the light is transmitted through a window 243 and a nozzle 244 to the interaction region. In certain embodiments, the laser head 200 comprises the window 243 and the nozzle 244 , while in other embodiments, the window 243 and the nozzle 244 are components of the containment plenum 240 .

[0084] In the embodiment schematically illustrated by FIG. 3C , the first mirror 235 reflects the light through an angle of approximately 90 degrees and the second mirror 235 ′ reflects the light through an angle of approximately −90 degrees such that the proximal portion 236 is substantially parallel to the distal portion 232 . In such embodiments, the light emitted by the containment plenum 240 is substantially parallel to, but displaced from, the light propagating through the distal portion 232 . Other embodiments have the first mirror 235 and the second mirror 235 ′ configured to reflect the light through other angles. Certain embodiments comprise a straight tubular portion between the first angle portion 234 and the second angle portion 234 ′ to provide additional displacement of the light emitted by the containment plenum 240 from the light propagating through the distal portion 232 .

[0085] In certain embodiments, the coupling between the distal portion 232 and the first angle portion 234 is rotatable. In certain other embodiments, the coupling between the first angle portion 234 and the second angle portion 234 ′ is rotatable. These rotatable couplings can comprise swivel joints which can be locked in position by thumbscrews. Such embodiments provide additional flexibility in directing the light emitted by the containment plenum 240 in a selected direction. In certain embodiments, the selected direction is non-planar with the light propagating through the distal portion 232 .

[0086] As described above, one or both of the first mirror 235 and the second mirror 235 ′ can be mounted on a removable assembly in certain embodiments to facilitate cleaning, maintenance, and replacement. In addition, the mountings of the first mirror 235 and/or the second mirror 235 ′ can be adjustable (e.g., using thumbscrews or Allen hex screws) so as to optimize the alignment and focus of the light beam. In certain embodiments, one or both of the first mirror 235 and the second mirror 235 ′ can also have a curvature or otherwise be configured so as to focus the light beam or otherwise modify the beam profile (e.g., beam shape).

[0087] In certain embodiments, one or more of the optical elements 220 within the laser head 200 (e.g., lens 212 , lens 233 , mirror 235 , mirror 235 ′) are water-cooled or air-cooled. Cooling water can be supplied by a heat exchanger located near the laser head 200 and dedicated to providing sufficient water flow to the laser head 200 . In certain such embodiments, the conduits for the cooling water for each of the optical elements 220 can be connected in series so that the cooling water flows sequentially in proximity to the optical elements 220 . In other embodiments, the conduits are connected in parallel so that separate portions of the cooling water flow in proximity to the various optical elements 220 . Exemplary heat exchangers include, but are not limited to a Miller Coolmate™ 4, available from Miller Electric Manufacturing Co. of Appleton, Wis. The flow rate of the cooling water is preferably at least approximately 0.5 gallons per minute.

[0088] Laser Head: Compact Configuration

[0089] FIG. 20 schematically illustrates another configuration of a laser head 1200 in accordance with embodiments described herein. Certain embodiments of the laser head 1200 are adapted to be movable and placed in position relative to the surface to be irradiated by a single person. In certain such embodiments, the combination of the laser head 1200 and certain embodiments of the anchoring mechanism 1110 , discussed below, weighs less than fifty pounds.

[0090] The embodiment illustrated by FIG. 20 is generally adapted for drilling holes in the surface to be irradiated, and is generally of smaller size and weight than the embodiments of FIGS. 3B and 3C , thereby providing an apparatus which is adapted to access more constrained spaces. In addition, the embodiment of FIG. 20 is generally more simple and more robust than the embodiments of FIGS. 3B and 3C , thereby providing an apparatus which is adapted to withstand rough handling and non-ideal operating conditions.

[0091] The laser head 1200 in certain embodiments comprises a generally rectangular housing 1230 . The other components of the laser head 1200 are positioned on the housing 1230 or within the housing 1230 . The housing 1230 of certain embodiments comprises a connection structure (not shown) which is adapted to be releasably coupled to an anchoring mechanism 1110 which, as described further below, is adapted to position the laser head 1200 relative to the surface to be irradiated. In an exemplary embodiment, the housing 1230 has a length of approximately 12 inches, a height of approximately 8 inches, and a width of approximately 4 inches. Other shapes and dimensions of the housing 1230 are compatible with embodiments described herein.

[0092] In certain embodiments, the laser head 1200 further comprises a connector 1210 which is adapted to be coupled to the conduit 400 carrying laser light from the laser generator 310 to the laser head 1200 . In certain embodiments, the connector 1210 comprises a lens (not shown) which collimates the diverging laser light emitted by the conduit 400 . As described above in relation to the extended configuration, the lens of various embodiments can comprise various materials, can be removably mounted to the housing 1230 , can be adjustably mounted to the housing 1230 , and can provide additional modification of the beam profile.

[0093] In certain embodiments, the laser head 1200 further comprises a first mirror 1235 adapted to reflect light from the connector 1210 through a first non-zero angle, and a second mirror 1235 ′ adapted to reflect light from the first mirror 1235 through a second non-zero angle to a nozzle 1244 which is adapted to be coupled to the containment plenum 240 . In certain embodiments, as schematically illustrated in FIG. 20 , the first non-zero angle is approximately equal to the negative of the second non-zero angle. Such two-mirror configurations are sometimes called “folded optics” configurations since reflecting the light between the mirrors effectively “folds” a propagation path having a length into a smaller space. Certain embodiments of the laser head 1200 comprise additional optical components adapted to modify the beam profile of the laser light.

[0094] As described above in relation to the extended configuration, at least one of the first mirror 1235 and the second mirror 1235 ′ is mounted in the housing 1230 on a removable and adjustable assembly. In addition, at least one of the first mirror 1235 and the second mirror 1235 ′ of certain embodiments has a curvature or is otherwise configured to modify the beam profile. At least one of the first mirror 1235 and the second mirror 1235 ′ of certain embodiments is cooled by either air or water provided by cooling conduits. In certain embodiments, the cooling conduits are contained within the housing 1230 , thereby facilitating transport and placement of the laser head 1200 by making the laser head 1200 less unwieldy and making the laser head 1200 more robust.

[0095] In certain embodiments, as shown in FIG. 21C , the laser head 1200 comprises a laser head handle 1240 coupled to the housing 1230 . The laser head handle 1240 is adapted to facilitate transporting and positioning the laser head 1200 at a selected location. Other configurations of the laser head handle 1240 are compatible with other embodiments described herein. The laser head 1200 of certain embodiments further comprises a coupler 1250 adapted to releasably couple the laser head 1200 to the anchoring mechanism 1110 . Other configurations of the laser head 1200 are compatible with embodiments described herein.

[0096] In certain embodiments, the compact configuration of the laser head (“compact laser head”) 1200 , such as shown in FIGS. 21A-21C , is advantageously used in certain applications rather than the extended configuration of the laser head (“extended laser head”) 200 as shown in FIGS. 3B and 3C . For example, when drilling holes in the structure, there may be areas in which the extended laser head 200 may not have access due to its length or other constraints (e.g., rigidity of the coupling between the energy conduit 400 and the connector 210 ). The compact laser head 1200 has a smaller volume, thereby allowing access to smaller areas.

[0097] In addition, in certain embodiments, the compact laser head 1200 is used in conjunction with an energy conduit 400 comprising a pivoting collimator head (not shown) adapted to provide a rotational coupling between the energy conduit 400 and the laser head 1200 . In such embodiments, the pivoting collimator head provides additional flexibility by allowing the laser head 1200 to access smaller areas. The collimator head can be straight, or can have an angle (e.g., 90 degrees). Using collimator heads with different orientations advantageously permits various orientations of the energy conduit 400 for providing access to constrained areas. Exemplary collimator heads compatible with embodiments described herein are available from Trumpf Lasertechnik GmbH of Ditzingen, Germany.

[0098] Furthermore, in certain embodiments, the compact laser head 1200 also incorporates the various sensors, proximity switches, and flow meters of the laser head 1200 within the housing 1230 . Such embodiments are generally more simple and more robust than the extended laser head 200 , thereby providing an apparatus which is adapted to withstand rough handling and non-ideal operating conditions, and is less likely to be damaged.

[0099] Laser Head: Lightweight Configuration

[0100] FIG. 21D schematically illustrates a combination of a lightweight laser head 2200 with an anchoring mechanism 1110 . In certain embodiments, the laser head 2200 has a 140-millimeter focal length and is commercially available, e.g., a D35 90-degree focus head with cooling and observation port available from Trumpf Lasertechnik GmbH of Ditzingen, Germany (Catalog No. 35902090). The laser head 2200 of certain embodiments is adapted for drilling relatively shallow holes. In certain embodiments, the laser head/anchoring mechanism combination weighs less than 10 pounds, while in other embodiments, the combination weighs approximately 8 pounds.

[0101] Laser Head: Containment Plenum

[0102] In certain embodiments, the laser head 200 comprises a containment plenum 240 coupled to the proximal portion 236 and which interfaces with the structure. In certain embodiments, the containment plenum 240 is adapted to confine material (e.g., debris and fumes generated during laser processing) removed from the structure and remove the material from the interaction region. The containment plenum 240 can also be further adapted to reduce noise and light emitted from the interaction region out of the containment plenum 240 (e.g., into the nominal hazard zone (“NHZ”) of the laser). One goal of the containment plenum 240 can be to ensure that no laser radiation in excess of the accessible emission limit (“AEL”) or maximum-permissible exposure (“MPE”) limit reaches the eye or skin of any personnel.

[0103] FIG. 4 schematically illustrates a cross-sectional view of a containment plenum 240 in accordance with embodiments described herein. The containment plenum 240 of FIG. 4 comprises a plenum housing 242 , a window 243 , a nozzle 244 , a resilient interface 246 , an extraction port 248 , and a compressed gas inlet 249 . The plenum housing 242 can be coupled to a source of laser light (e.g., the proximal portion 236 of the laser head 200 ) and can provide structural support for the other components of the containment plenum 240 . Exemplary materials for the plenum housing 242 include, but are not limited to, metals (e.g., aluminum, steel) which can be in the form of thin flexible sheets, ceramic materials, glass or graphite fibers, and fabric made from glass or graphite fibers. In certain embodiments, the plenum housing 242 is either air-cooled or water-cooled to reduce heating of the plenum housing 242 . Coolant conduits for the plenum housing 242 can be coupled in series or in parallel with the coolant conduits for other components of the laser head 200 .

[0104] The window 243 of certain embodiments is positioned upstream of the nozzle 244 and within the propagation path of the laser light from the proximal portion 236 to the structure. As used herein, the terms “downstream” and “upstream” have their ordinary meanings referring to the propagation direction of the laser light and to the direction opposite to the propagation direction of the laser light, respectively. In such embodiments, the light propagating through the containment plenum 240 reaches the window 243 prior to reaching the nozzle 244 . In such embodiments in which the light propagates downstream through the window 243 , the window 243 is substantially transparent to the laser light. The window 243 can be mounted within the plenum housing 242 to transmit the laser light in the downstream direction. The window 243 can have a number of shapes, including, but not limited to, square and circular. Exemplary windows 243 include, but are not limited to, a silica window (e.g., Part No. W2-PW-2037-UV-1064-0 available from CVI Laser Corp. of Albuquerque, N.M.).

[0105] Dust and/or dirt on the optical elements of the laser head 200 can absorb an appreciable fraction of the laser light, resulting in nonuniform heating which can damage the optical elements. In certain embodiments, the window 243 is mounted within the plenum housing 242 to provide a barrier to the upstream transport of dust, smoke, or other particulate matter generated by the interaction of the laser light and the structure. In this way, the window 243 can facilitate protection of the upstream optical elements within the other portions of the laser head 200 .

[0106] The window 243 can be mounted in a removable assembly in certain embodiments to facilitate cleaning, maintenance, and replacement of the window 243 . In certain embodiments, the window 243 focuses the light received from the proximal portion 236 , while in other embodiments, the window 243 can provide additional modification of the beam profile (e.g., beam shape). In such embodiments, the mounting of the window 243 can be adjustable (e.g., using thumbscrews or Allen hex screws) so as to optimize the alignment and focus of the light beam. Exemplary window mounting assemblies include, but are not limited to, Part Nos. PLALH0097 and PLFLH0119 available from Laser Mechanisms, Inc. of Farmington Hills, Mich. In certain embodiments, the window 243 is either air-cooled or water-cooled.

[0107] The laser light transmitted through the window 243 is emitted through the nozzle 244 towards the interaction region of the structure. The laser light can be focussed near the opening of the nozzle 244 . Exemplary materials for the nozzle 244 include, but are not limited to metals (e.g., copper). In certain embodiments, the nozzle 244 is either air-cooled or water-cooled to reduce heating of the nozzle 244 . Coolant conduits for the nozzle 244 can be coupled in series or in parallel with the coolant conduits for other components of the laser head 200 .

[0108] The laser light propagating through the nozzle 244 preferably does not impinge the nozzle 244 (termed “clipping”) to avoid excessively heating and damaging the nozzle 244 . Improper alignment of the laser light through the laser head 200 can cause clipping. The opening of the nozzle 244 can be sufficiently large so that the laser light does not appreciably interact with the nozzle 244 . In certain embodiments, the nozzle 244 is approximately 0.3 inches in diameter.

[0109] In certain embodiments, the resilient interface 246 of the containment plenum 240 is adapted to contact the structure and to substantially surround the interaction region, thereby facilitating confinement and removal of material from the interaction region. In addition, the resilient interface 246 can facilitate blocking light and/or sound from escaping outside the containment plenum 240 . Exemplary resilient interfaces 246 include, but are not limited to, a wire brush.

[0110] In certain embodiments, the extraction port 248 of the containment plenum 240 is adapted to extract an appreciable portion of the material (e.g., gas, vapor, dust, and debris) generated within the interaction region during operation. The extraction port 248 can be coupled to a vacuum generator (not shown) which creates a vacuum to pull material (e.g., airborne particulates, gases, and vapors) from the interaction region. In this way, the extraction port 248 can provide a pathway for removal of the material from the containment plenum 240 .

[0111] In certain embodiments, the compressed gas inlet 249 is adapted to provide compressed gas (e.g., air) to the containment plenum 240 . In certain embodiments, the compressed gas inlet 249 is fluidly coupled to the nozzle 244 which is adapted to direct a compressed gas stream to the interaction region. In certain embodiments, compressed gas flows coaxially with the laser light through the nozzle 244 . The window 243 of certain embodiments provides a surface against which the compressed gas exerts pressure. In this way, the compressed gas can flow through the nozzle 244 to the interaction region at a selected pressure and velocity.

[0112] The compressed gas flowing from the compressed gas inlet 249 through the nozzle 244 can be used to deter dust, debris, smoke, and other particulate matter from entering the nozzle 244 . In this way, the compressed gas can facilitate protection of the window 243 from such particulate matter. In addition, the compressed gas can be directed by the nozzle 244 to the interaction region so as to facilitate removal of material from the interaction region. The nozzle 244 can be used in this manner in embodiments in which the structure includes concrete with a high percentage of Si, so that the resultant glassy slag is sufficiently viscous and more difficult to remove from the interaction region.

[0113] In certain embodiments, the compressed air is substantially free of oil, moisture, or other contaminants to avoid contaminating the surface of the window 243 and potentially damaging the window 243 by nonuniform heating. An exemplary source of instrument quality (“IQ”) compressed air is the 300-IQ air compressor available from Ingersoll-Rand Air Solutions Group of Davidson, N.C. The source of compressed air preferably provides air at a sufficient flow rate determined in part by the length of the hose delivering the air, and the number of components using the air and their requirements.

[0114] In certain embodiments, the air compressor can be located hundreds of feet away from the laser head 200 . In such embodiments, the source of compressed air can comprise an air dryer to reduce the amount of moisture condensing in the air conduits or hoses between the air compressor and the laser head 200 . An exemplary air dryer in accordance with embodiments described herein is the 400 HSB air dryer available from Zeks Compressed Air Solutions of West Chester, Pa.

[0115] In certain embodiments, as schematically illustrated in FIG. 5 , the laser head 200 comprises a sensor 250 adapted to measure the relative distance between the laser head 200 and the interaction region. FIG. 5 schematically illustrates an embodiment in which the containment plenum 240 comprises the sensor 250 , although other locations of the sensor 250 are also compatible with embodiments described herein. As material is removed from the structure, the interaction region extends into the structure. The sensor 250 then provides a measure of the depth of the interaction region from the surface of the structure. The sensor 250 can use various technologies to determine this distance, including, but not limited to, acoustic sensors, infrared sensors, tactile sensors, and imaging sensors. In certain embodiments in which laser scabbling or machining is performed, a sensor 250 comprising a diode laser and utilizing triangulation could be used to determine the distance between the laser head 200 and the surface being processed. Such a sensor 250 can also provide a measure of the amount of material removed from the surface.

[0116] In certain embodiments, the sensor 250 is coupled to the controller 500 , and the controller 500 is adapted to transmit control signals to the laser base unit 300 in response to signals from the sensor 250 . The laser base unit 300 can be adapted to adjust one or more parameters of the laser light in response to the control signals. In this way, the depth information from the sensor 250 can be used in real-time to adjust the focus or other parameters of the laser light.

[0117] In other embodiments, the controller 500 is adapted to transmit control signals to the laser manipulation system 100 in response to signals from the sensor 250 . The laser manipulation system 100 is adapted to adjust the relative distance between the laser head 200 and the interaction region in response to the control signals. In addition, the laser manipulation system 100 can be adapted to adjust the position of the laser head 200 along the surface of the structure in response to the control signals. In this way, the depth information from the sensor 250 at a first location can be used in real-time to move the laser light to another location along the surface once a desired depth at the first location is achieved.

[0118] In other embodiments, the sensor 250 is used in conjunction with statistical methods to determine the depth of the interaction region. In such embodiments, the sensor 250 is first used in a measurement phase to develop statistical data which correlates penetration depths with certain processing parameters (e.g., material being processed, light intensity). During the measurement phase, selected processing parameters are systematically varied for processing a test or sample surfaces indicative of the surfaces of the structure to be processed. The sensor 250 is used in the measurement phase to determine the depth of the interaction region corresponding to these processing parameters. In certain such embodiments, the sensor 250 can be separate from the laser head 200 , and can be used during the processing of the structure or during periods when the processing has been temporarily halted in order to measure the depth of the interaction region. Exemplary sensors 250 compatible with such embodiments include, but are not limited to, calipers or other manual measuring devices which are inserted into the resultant hole to determine the depth of the interaction region.

[0119] In certain embodiments, the controller 500 contains this resulting statistical data regarding the correlation between the processing parameters and the depth of the interaction region. During a subsequent processing phase, the structure is processed, but rather than using the sensor 250 at this time, the controller 500 can be adapted to determine the relative distance by accessing the statistical data corresponding to the particular processing parameters being used. Such an approach represents a reliable and cost-effective approach for determining the depth of the interaction region while processing the structure.

[0120] In alternative embodiments, the sensor 250 is adapted to provide a measure of the distance between the laser head 200 and the surface of the structure. In such embodiments, the sensor 250 can be adapted to provide a fail condition signal to the controller 500 upon detection of the relative distance between the laser head 200 and the structure exceeding a predetermined distance. Such a fail condition may result from the apparatus 50 inadvertently becoming detached from the structure. The controller 500 can be adapted to respond to the fail condition signal by sending appropriate signals to the laser base unit 300 to halt the transmission of energy between the laser base unit 300 and the laser head 200 . In certain embodiments, the transmission is preferably halted when the laser head 200 is further than one centimeter from the surface of the structure. In this way, the apparatus 50 can utilize the sensor 250 to insure that laser light is not emitted unless the containment plenum 240 is in contact with the structure. In certain embodiments, the sensor 250 comprises a proximity switch which contacts the surface of the structure while the apparatus 50 is attached to the structure.

Laser Manipulation System (LMS)

[0121] LMS: Combined Anchoring Mechanism and Positioning Mechanism

[0122] In certain embodiments, the laser manipulation system 100 serves to accurately and repeatedly position the laser head 200 in relation to the structure so as to provide articulated robotic motion generally parallel to the surface to be processed. To do so, the laser manipulation system 100 can be releasably affixed to the structure to be processed, and can then accurately move the laser head 200 in proximity to that surface. FIGS. 6A and 6B schematically illustrate two opposite elevated perspectives of an embodiment in which the laser manipulation system 100 comprises an anchoring mechanism 110 adapted to be releasably coupled to the structure and a positioning mechanism 121 coupled to the anchoring mechanism 110 and coupled to the laser head 200 . In certain embodiments, the laser manipulation system 100 can be advantageously disassembled and reassembled for transport, storage, or maintenance.

[0123] Anchoring Mechanism

[0124] Certain embodiments of the laser manipulation system 100 comprise an anchoring mechanism 110 to releasably affix the laser manipulation system 100 to the structure to be processed. The anchoring mechanism 110 can be adapted to be releasably coupled to the structure and can comprise one or more attachment interfaces 111 .

[0125] In the embodiment schematically illustrated in FIG. 6B , the anchoring mechanism 110 comprises a pair of attachment interfaces 111 . Each attachment interface 111 comprises at least one resilient vacuum pad 112 , at least one interface mounting device 114 , at least one vacuum conduit 116 , at least one mounting connector 118 , and a coupler 119 adapted to couple the attachment interface 111 of the anchoring mechanism 110 to the positioning mechanism 121 . While the embodiment schematically illustrated in FIGS. 6A and 6B have two vacuum pads 112 for each of the two attachment interfaces 111 , other embodiments utilize any configuration or number of attachment interfaces 111 and vacuum pads 112 .

[0126] In the embodiment illustrated by FIG. 7 , two vacuum pads 112 are coupled to the interface mounting device 114 . In certain embodiments, each vacuum pad 112 comprises a circular rubber pad which forms an effectively air-tight region when placed on the structure. Each vacuum pad 112 is fluidly coupled to at least one vacuum generator (not shown) via a vacuum conduit 116 (e.g., a flexible hose). The vacuum generator may use fluid power (e.g., compressed air) to generate the vacuum, or it may use an external vacuum source. The vacuum generator draws air out from the air-tight region between the vacuum pad 112 and the structure via the vacuum conduit 116 , thereby creating a vacuum within the air-tight region. Atmospheric pressure provides a force which reversibly affixes the vacuum pad 112 to the structure.

[0127] The interface mounting device 114 comprises a rigid metal support upon which is mounted the vacuum pads 112 , the mounting connector 118 , and the coupler 119 . In certain embodiments, the mounting connector 118 can comprise a ground-based support connector 118 a adapted to be releasably attached to a ground-based support system 700 , as described more fully below. In other embodiments, the mounting connector 118 can comprise at least one suspension-based support connector 118 b adapted to be releasably attached to a suspension-based support system 800 , as described more fully below. The coupler 119 is adapted to releasably couple the interface mounting device 114 to the positioning mechanism 121 . In certain embodiments, the coupler 119 comprises at least one protrusion which is connectable to at least one corresponding recess in the positioning mechanism 121 .

[0128] In alternative embodiments, the anchoring mechanism 110 can comprise other technologies for anchoring the apparatus 50 to the structure to be processed. These other technologies include, but are not limited to, a winch, suction devices (e.g., cups, gekkomats, or skirts) affixed to the apparatus 50 or on quasi-tank treads, mobile scaffolding suspended from the structure, and a rigid ladder. These technologies can also be used in combination with one another in certain embodiments of the anchoring mechanism 110 .

[0129] Positioning Mechanism

[0130] Certain embodiments of the laser manipulation system 100 comprise a positioning mechanism 121 to accurately move the laser head 200 while in proximity to the structure to be processed. FIG. 8 schematically illustrates an exploded view of one embodiment of the positioning mechanism 121 along with the attachment interfaces 111 of the anchoring mechanism 110 . The positioning mechanism 121 of FIG. 8 comprises a first-axis position system 130 , a second-axis position system 150 , an interface 140 , and a laser head receiver 220 . The first-axis position system 130 is releasably coupled to the attachment interfaces 111 of the anchoring mechanism 110 by at least one coupler 132 . The interface 140 (comprising a first piece 140 a and a second piece 140 b in the embodiment of FIG. 8 ) releasably couples the second-axis position system 150 to the first-axis position system 130 . The laser head receiver 220 is releasably coupled to the second-axis position system 150 , and is adapted to be releasably coupled to the housing 230 of the laser head 200 .

[0131] In certain embodiments, the first-axis position system 130 comprises at least one coupler 132 having a recess which is releasably connectable to at least one corresponding protrusion of the coupler 119 of the anchoring mechanism 110 . Such embodiments are advantageously disassembled and reassembled for transport, storage, or maintenance of the positioning mechanism 121 . Other embodiments can have the first-axis position system 130 fixedly coupled to the anchoring mechanism 110 .

[0132] In certain embodiments, the first-axis position system 130 moves the laser head 200 in a first direction substantially parallel to the surface of the structure. In the embodiment schematically illustrated by FIG. 9 , the first-axis position system 130 further comprises a first rail 134 , a first drive 136 , and a first stage 138 . The first stage 138 is movably coupled to the first rail 134 under the influence of the first drive 136 . The first piece 140 a of the interface 140 is fixedly coupled to the first stage 138 so that the first drive 136 can be used to move the interface 140 along the first rail 134 . In certain embodiments, the first-axis position system 130 further comprises sensors, limit switches, or other devices which provide information regarding the position of the first stage 138 along the first rail 134 . This information can be provided to the controller 500 , which is adapted to transmit control signals to the first drive 136 or other components of the laser manipulation system 100 in response to this information.

[0133] Exemplary first drives 136 include, but are not limited to, hydraulic drives, pneumatic drives, electromechanical drives, screw drives, and belt drives. First rails 134 , first drives 136 , and first stages 138 compatible with embodiments described herein are available from Tol-O-Matic, Inc. of Hamel, Minn. Other types and configurations of first rails 134 , first drives 136 , and first stages 138 are also compatible with embodiments described herein.

[0134] In certain embodiments, the second-axis position system 150 moves the laser head 200 in a second direction substantially parallel to the surface of the structure. The second direction in certain embodiments is substantially perpendicular to the first direction of the first-axis position system 130 . In the embodiment schematically illustrated by FIG. 10 , the second-axis position system 150 comprises a second rail 152 , a second drive 154 , and a second stage 156 . In certain embodiments, the first-axis position system 130 and the second-axis position system 150 provide linear movements of the laser head 200 . In other embodiments, the first-axis position system 130 and the second-axis position system 150 provide circular and axial movements of the laser head 200 , respectively.

[0135] In certain embodiments, the second stage 156 is movably coupled to the second rail 152 under the influence of the second drive 154 . The laser head receiver 220 is releasably coupled to the second stage 156 so that the second drive 154 can be used to move the laser head receiver 220 along the second rail 152 . In certain embodiments, the second-axis position system 150 further comprises sensors, limit switches, or other devices which provide information regarding the position of the second stage 156 along the second rail 152 . This information can be provided to the controller 500 , which is adapted to transmit control signals to the second drive 154 or other components of the laser manipulation system 100 in response to this information.

[0136] Exemplary second drives 154 include, but are not limited to, hydraulic drives, pneumatic drives, electromechanical drives, screw drives, and belt drives. Second rails 152 , second drives 154 , and second stages 156 compatible with embodiments described herein are available from Tol-O-Matic, Inc. of Hamel, Minn. Other types and configurations of second rails 152 , second drives 154 , and second stages 156 are also compatible with embodiments described herein.

[0137] In certain embodiments, the second rail 152 is fixedly coupled to the second piece 140 b of the interface 140 . The second piece 140 b can comprise at least one recess which is releasably connectable to at least one corresponding protrusion of the first piece 140 a of the interface 140 . Such embodiments are advantageously disassembled and reassembled for transport, storage, or maintenance of the positioning mechanism 121 . In other embodiments, the interface 140 can be made of a single piece which is releasably coupled to one or both of the first stage 138 and the second rail 152 . Other embodiments are not configured for convenient disassembly (e.g., having an interface 140 made of a single piece and that is fixedly coupled to both the first stage 138 and the second rail 152 ).

[0138] In certain embodiments, the interface 140 comprises a tilt mechanism 144 to adjust the relative orientation between the first rail 134 and the second rail 152 . As schematically illustrated in FIG. 11A , the first piece 140 a of the interface 140 is coupled to the first stage 138 on the first rail 134 , and comprises a pair of protuberances 142 adapted to couple with corresponding recesses of the second piece 140 b of the interface 140 . The tilt mechanism 144 comprises a first plate 145 , a hinge 146 , a second plate 147 , and a pair of support braces 148 . The first plate 145 is fixedly mounted to the first stage 138 and is substantially parallel to the surface upon which the anchoring mechanism 110 is mounted. The second plate 147 is pivotally coupled to the first plate 145 by the hinge 146 , and can be locked in place by the support braces 148 .

[0139] In FIG. 11A , the tilt mechanism 144 is configured so that the first plate 145 and the second plate 147 are substantially parallel to one another. In this configuration, the plane of movement defined by the first direction and the second direction of the laser head 200 is substantially parallel to the surface upon which the anchoring mechanism 110 is coupled. In FIG. 11B , the tilt mechanism 144 is configured so that the second plate 147 is at a non-zero angle (e.g., 90 degrees) relative to the first plate 145 . In this configuration, the plane of movement defined by the first direction and the second direction of the laser head 200 is at a non-zero angle relative to the surface upon which the anchoring mechanism 110 is coupled.

[0140] In certain embodiments, the laser head receiver 220 is releasably coupled the housing 230 of the laser head 200 . FIG. 12 schematically illustrates a laser head receiver 220 compatible with embodiments described herein. The laser head receiver 220 is coupled to the second stage 156 and comprises a releasable clamp 222 and a third-axis position system 224 . The clamp 222 is adapted to hold the housing 230 of the laser head 200 . The third-axis position system 224 is adapted to adjust the relative distance between the laser head 200 and the structure being processed. In certain embodiments, the third-axis position system 224 comprises a screw drive which moves the clamp 222 substantially perpendicularly to the second rail 152 . In certain embodiments, as schematically illustrated by FIG. 12 , the screw drive is manually actuated by a handle 226 , which can be rotated to move the clamp 222 . In other embodiments, the screw drive is automatically controlled by equipment responsive to control signals from the controller 500 .

[0141] Ground-Based Support System

[0142] In certain embodiments, the apparatus 50 can be utilized with a ground-based support system 700 which is releasably coupled to the apparatus 50 . The interface mounting devices 114 can each comprise a ground-based support connector 118 a adapted to releasably couple to the ground-based support system 700 . The ground-based support system 700 advantageously attaches to various types of external boom systems, such as commercially-available lifting- or positioning-type systems, which can support some of the weight of the apparatus 50 , thereby reducing the weight load supported by the anchoring mechanism 110 . The ground-based support system 700 can be used to facilitate use of the apparatus 50 on substantially vertical surfaces (e.g., walls) or on substantially horizontal surfaces (e.g., ceilings).

[0143] In certain embodiments, the ground-based support system 700 includes a support structure 710 such as that schematically illustrated in FIG. 13 . The support structure 710 of FIG. 13 comprises a boom connector 712 , a rotational mount 714 , a spreader member 716 , a pair of primary posts 718 , and a pair of auxiliary posts 720 . The boom connector 712 is adapted to attach to a selected external boom system. The rotational mount 714 is adapted to be rotatably coupled to the boom connector 712 and fixedly coupled to the spreader member 716 so that the boom connector 712