Optical alignment system for power tool

[0001] Recent patents disclose the use of lasers for alignment purposes in various applications. For example, U.S. Pat. No. 5,741,096 discloses a line-laser assisted alignment apparatus for a drill bit, and U.S. Pat. No. 5,320,111 discloses a light beam locator and guide for a biopsy needle.

[0002] As the use of lasers in commonly used power tools increases, there is a need for providing an optical alignment system that is compact, cost-effective and user friendly.

[0003] One embodiment of the invention provides a power tool having a work surface and a spindle defining an axis of operation of the power tool and facing the work surface. The power tool may include a bracket attached to the power tool above the work surface. The bracket may include first and second bracket receptacles, a first holder movably supported in the first bracket receptacle, and a second holder movably supported in the second bracket an axis of the first holder, and it may adjustably project a first fan beam. A second laser generator may be mounted in the send holder at a second angle relative to an axis of the second holder, and it may adjustably project a second fan beam. The first and second fan beams may be adjusted to intersect along the axis of operation of the power tool.

[0022] Referring now to the drawings for the purpose of illustrating various embodiments of the invention and not for the purpose of limiting the same, it is to be understood that standard components or features that are within the purview of an artisan of ordinary skill and do not contribute to the understanding of the various embodiments of the invention are omitted from the drawings to enhance clarity. In addition, it will be appreciated that the characterizations of various components and orientations described herein as being “vertical” or “horizontal”, “right” or “left”, “side”, “top” or “bottom”, are relative characterizations only based upon the particular position or orientation of a given component for a particular application.

[0023] FIG. 1 depicts an embodiment of a power tool 100 having a table or a work surface 102 and a tool holder or spindle 104. The spindle 104 may be supported on a quill 106 that is movably attached to a head 108 of the power tool 100. The quill 106 may be moved in the directions indicated by arrows “C” by using a crank or lever mechanism 110 in a known manner. The spindle 104 defines an axis “A—A” of operation of the power tool 100 and may include a chuck portion for supporting a tool 112, such as, for example, a drill bit, or an alignment rod 113 which may be used before operating the power tool 100 as is discussed in connection with FIG. 15.

[0024] The power tool 100 may comprise any type of power tool or cutter having an axis of operation A—A, such as, for example, a drill press, a gang drill, a turret drill, a multiple-spindle drill, a boring machine, a band saw, etc.

[0025] An embodiment of an optical alignment system 200 of the present invention may be mounted on the power tool 100. See FIGS. 1-2. The optical alignment system 200 may include a bracket 202 for supporting two laser generators 204 that each have longitudinal axes designated as “D—D”. In one embodiment, the bracket 202 may include two spaced-apart open-ended receptacles 208. in one embodiment, for example, the centers of the receptacles 208 are separated by a distance “L”. See FIGS. 5 and 6. Each receptacle 208 may include a cylindrical portion 209 that extends below the lower surface of the bracket 202 and defines an inner seat 214. Each receptacle 208 may receive a holder 206 in which a corresponding laser generator 204 is mounted. See FIGS. 7 and 8. In one embodiment, the holder 206 may include a plurality of snap fit pillars 210 that are arranged to receive and hold a laser generator 204 such that its longitudinal axis D—D defines a desired dip angle β relative to a holder axis B-B. The dip angle β may be chosen to be, for example, 45 degrees. See FIG. 2.

[0026] Each laser generator 204 may comprise a commercial laser generator of the type that produces a fan beam of light, such as the laser line generators manufactured by Sean & Stephen Corporation of Taiwan and China under Model 1894. However. Other commercially available generators could be employed. In one embodiment, the laser generator 204 may be customized to include a handle or knob arrangement 220 that may be attached to a barrel 222 that encloses the laser unit 224 of the laser generator 204. See FIGS. 9 and 10. Such handle 220 can facilitate any adjustment of the laser generator 204 within its holder 206.

[0027] The laser generators 204 may be powered by a battery or by the power source of the power tool via electrical cables connected to electrical system of the power tool (not shown). In the latter case, an AC to DC converter may be required, as well as an appropriately sized voltage reducer.

[0028] As can be seen in FIGS. 7 and 8, one embodiment, the holder 206 may have a cylindrical rim 212 that extends around the perimeter of the seat 214 of the receptacle 208. The rim 212 may include an opening 216 to facilitate insertion of the laser generator 204 into the holder 206 at the desired dip angle β. The holder 206 may also include a bottom notch 218 to allow unobstructed passage of light from the laser generator 204 to a workpiece that is supported on the table 102 as will be further discussed below.

[0029] In one embodiment, the optical alignment system 200 may also include a holder cover 226. See FIGS. 11 and 12. The holder cover 226 may be sized to fit over and cover the holder 206 with the laser generator 204 mounted therein. As can be seen in FIG. 2, the holder cover 226 may be attached to the bracket 202 with conventional fasteners 232, such as, for example, screws or bolts, which pass through holes 230 in the holder cover 226 and are received in corresponding holes 228 of the bracket 202. It will be appreciated that other fasteners, such as, for example, hook and loop attachments may be also used. In one embodiment, the holder cover 226 may include a tab 246 that protrudes from the surface of the holder cover 226 to face the holder 206 when the holder cover 226 is attached to the bracket 202. When the holder cover 226 is attached to the bracket 202, the tab 246 prevents accidental rotation of the laser generator 204. The holder cover 226 may also prevent rotation of the holder 206 when it is attached on the bracket 202.

[0030] In the embodiment shown in FIGS. 1 and 2, the bracket 202 may be rotatably attached to the moving quill 106 of the power tool with an end cap 234. As can be seen in FIG. 2, the end cap 234 include a semi-cylindrical surface 236 that is connected in registry with a corresponding semi-cylindrical surface 238 of the bracket 202 forming an opening sized to receive the quill 106. The end cap 234 may be attached to the bracket 202 with fasteners 240 through corresponding holes 242 and 244 in the end cap 234 and the bracket 202. By loosening or removing the fasteners 240, the bracket 202 may be moved to a different position along the quill 106 or may be rotated about the operation axis A-A, when, for example, it is necessary to accommodate an oddly-shaped workpiece.

[0031] In one embodiment, the optical alignment system 200 may also include a bracket cover 250 attached to the bottom of the bracket 202 with conventional fasteners (not shown), which may be inserted through a plurality of holes 254 to fasten the bracket cover 250 to the bracket 202 in corresponding holes 256 on the bottom of the bracket. See FIGS. 2, 5 and 13. The bracket cover 250 may include openings 252 that are sized to fit over the cylindrical portions 209 of the receptacles 208. The bracket cover 250 may also include a curved surface 258 shaped to fit around the quill 106, when the bracket 202 is attached to the quill 106. In one embodiment, the bracket 202 may also include one or more reinforcing ribs 203.

[0032] Another embodiment of the optical alignment system 300 is shown in FIGS. 3, 4 and 14. In this embodiment, the optical alignment system 300 has a bracket 302 that is adapted to be attached to the underside of the head 108 of the power tool 100, but may include laser generators 204, holders 206, receptacles 208, and holder covers 226 of the types described above. The bracket 302 may include an attachment element 360 that has mounting holes 362 for attaching the bracket 302 to the underside of the head 108, by means of threaded fasteners or the like (not shown). Alternatively, the bracket 302 may be cast as an integral part of the underside of the head 108 of the power tool 100.

[0033] In operation, the optical alignment system 200 may be powered such that each laser generator 204 projects a fan beam of light in the form of a fan plane 280. See FIG. 15. Each of the laser generators 204 may be rotated about its respective axis D—D, until the corresponding fan plane 280 is parallel to the operation axis A—A. Each holder 206 may then be rotated about its axis B—B until the corresponding fan plane 280 passes through the operation axis A—A. In this position, the fan planes 280 intersect along the operation axis A—A, projecting two intersecting lines of light 282 on the table 102 or on a workpiece 103 that is supported by the table 102. The lines of light 282 intersect at an angle γ at a point of intersection “P” that indicates the position for the operation of the tool 112 that is mounted on the spindle 104. The magnitude of the angle γ depends upon the distance L that separates the receptacles 208 in the bracket 202 and the distance between the receptacles 208 and the operation axis A—A. In one embodiment, an alignment rod 113 may be supported by the spindle 104 prior to operation to guide the adjustment process of the optical alignment system 200.

[0034] After the laser generators 204 have been oriented in the above described manner such that they project the intersecting lines 282 that intersect at the point P through which the operation axis A—A extends, the user may place the workpiece 103 on the table 102. Presumably, the user may have marked a portion of the workpiece 103 with a reference mark for designation the exact point at which the tool 112 is to contact and act upon the workpiece. For example, in the case of a drill arrangement of the type depicted in FIG. 1, the user places the pre-marked workpiece 103 on the table 102 and manipulates it to a position wherein the point of intersection P between the intersecting lines 282 coincides with the point marked on the workpiece 103. The workpiece 103 is then held in that position while the user advances the powered drill bit 112 through the workpiece 103 to drill the desired hole therethrough. The reader will readily appreciate that the optical alignment system permits the user to accurately and quickly position the workpiece 103 to achieve the desired results.

[0035] As can be seen in FIGS. 16 and 17, one embodiment of the optical alignment system 400 includes a bracket 402 that has one or more spacing connectors 470 that movably connect two outer portions 474 of the bracket 402 with a center portion 472 of the bracket 402. The outer portions 474 include corresponding receptacles 408 for the laser generators and their holders, which may be of the types and construction described above. The spacing connectors 470 may include for example, telescoping arms, or spring-loaded extenders or other spacer devices which may be used to change the distance L that separates the receptacles 408 (or the corresponding holders and laser generators) without removing the bracket 402 from the power tool 100. Accordingly, the angle of intersection γ may be adjusted as desired during the operation of the optical alignment system 400. FIGS. 16 and 17 illustrate an embodiment of the optical alignment system 400 that includes an end cap 434 for attaching the bracket 402 to the quill 106. It will be appreciated, however, that spacing connectors 470 may also be included in embodiments in which to optical alignment system is attached to the head 108 of the power tool 100, as in the embodiments depicted in FIGS. 3, 4 and 14.

[0036] The optical alignment systems 200, 300, 400 of the present invention provide a compact, space-saving, cost-effective and easy to use alignment capability to any type of tool that operates along an axis.

[0037] Whereas particular embodiments of the invention have been described herein for the purpose of illustrating the invention and not for the purpose of limiting the same, it will be appreciated by those of ordinary skill in the art that numerous variations of the details, materials and arrangement of parts may be made within the principle and scope of the invention without departing from the spirit of the invention. The preceding description, therefore, is not meant to limit the scope of the invention. Rather the scope of the invention is to be determined only by the appended claims and their equivalents.