Miter saw alignment system

• US 5,285,708 A
• Filed: 05/18/1992
• Issued: 02/15/1994
• Est. Priority Date: 05/18/1992
• Status: Expired due to Term

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Porter-Cable Corporation (Stanley Black & Decker, Inc.)
• Inventors: Nichols, James P. Jr., Plume, Steven H., Popik, Matthew G., Huntsman, Dennis C., Cooper, Randy G., Schnell, John W., Keller, David V., Kriaski, John R., Bosten, Donald R.
• Primary Examiner(s): Jones, Eugenia
• Application Number:
  US07/855,313
• Time in Patent Office: 638 Days
• Field of Search: 83/520, 83/521, 83/471.3, 83/478, 83/490, 83/397, 362/89, 362/259, 362/287
• US Class Current: 83/520
• CPC Class Codes: B23D 33/12 Equipment for indicating where to cut
• CPC Class Codes: B23D 59/003 Indicating the cutting plane on the workpiece, e.g. by projecting a laser beam
• CPC Class Codes: B27B 31/06 Adjusting equipment, e.g. using optical projection see also B27L5/022
• CPC Class Codes: Y10T 83/7697 Tool angularly adjustable relative to work-support
• CPC Class Codes: Y10T 83/7788 Tool carrier oscillated or rotated
• CPC Class Codes: Y10T 83/828 With illuminating or viewing means for work

Abstract

A miter saw with an optical system for projecting an optical alignment marker onto a workpiece. The miter saw has a base, a turntable rotatably supported by the base, a fence disposed above the base for supporting the orientation of the workpiece located on the base, a support coupled to the rear portion of the turntable, and a cutting apparatus including a blade for cutting the workpiece. The cutting apparatus is pivotally coupled to the support for positioning the blade from a raised position above the workpiece to an operational position for engagement with the workpiece. The light projection system is attached to the cutting apparatus for projecting an optical alignment marker onto the workpiece so that the location at which the blade engages the workpiece is in a selectably adjustable relationship with respect to the position of the optical alignment marker on the workpiece. A belt-driven embodiment of the miter saw has an adjustable pulley system comprising a motor connected to a drive pulley, a blade pulley connected to the blade, the blade pulley being in substantial alignment with the drive pulley, and a belt for connecting the drive pulley with the blade pulley. An adjustment mechanism for adjusting the distance between the drive pulley and the blade pulley is provided so that the tension on the drive belt may be adjusted.

Claims

1. A miter saw with an optical system for projecting an optical alignment marker onto a workpiece, comprising:

a base;

a turntable rotatably supported by the base, the turntable having a front and rear portion;

a fence disposed above the base for supporting the orientation of the workpiece located on the base;

a support coupled to the rear portion of the turntable;

cutting means including a blade for cutting the workpiece, the cutting means being pivotally coupled to the support for positioning the blade from a raised position above the workpiece to an operational position for engagement with the workpiece to an operational position for engagement with the workpiece, the blade having a radius, two sides, and a width and the cutting means having a front and rear portion; and

light projecting means attached to the cutting means for projecting a planar beam of light past one side of the blade and onto the workpiece in order to form a linear optical alignment marker on the workpiece, the linear optical alignment marker having a thickness and two sides, the light projection means further comprising adjustment means for adjusting the alignment marker so that the side of the alignment marker facing the blade is coincident with a plane defined by the one side of the blade, whereby the side of the linear optical alignment marker that is coincident with the plane defined by the one side of the blade will designate the location at which the one side of the blade will enter the workpiece.

2. The apparatus of claim 1 wherein the light projection means comprises laser means for projecting a coherent beam of visible light.

3. The apparatus of claim 2 wherein the laser means includes optical means comprising a line generator for converting the beam into a linear alignment marker having generally linear configuration substantially parallel to the blade.

4. The apparatus of claim 3 wherein the length of the linear alignment marker generally corresponds to the distance from the front to the rear portion of the turntable when the blade is in the raised position.

5. The apparatus of claim 2 wherein the laser means includes sensor means for sensing high temperature and low temperature conditions and for terminating operation of the laser means in response to temperatures above the high temperature condition or below the low temperature condition.

6. The apparatus of claim 1 wherein the adjustment means includes means for adjusting the special relationship between the optical alignment marker and the blade.

7. The apparatus of claim 1 wherein the adjustment means includes rotational adjustment means for moving the location of the optical alignment marker on the workpiece along an axis perpendicular to the blade.

8. The apparatus of claim 1 wherein the adjustment means includes rotational adjustment means for rotating the light projection means in order to adjust the parallelism of the optical alignment marker with respect to a side surface of the blade.

9. The apparatus of claim 1 wherein the adjustment means includes lateral adjustment means for moving the light projection means along an axis perpendicular to the blade.

10. The apparatus of claim 9 wherein the lateral adjustment means comprises slide means for sliding the light projection means laterally.

11. The apparatus of claim 9 wherein the lateral adjustment means includes biasing means for securing the light projection means at a particular location.

12. The apparatus of claim 9 wherein tho lateral adjustment means includes end stops to limit the lateral movement of the light projection means.

13. The apparatus of claim 9 wherein the lateral adjustment means comprises means for adjusting the lateral position of the light projection means to be positioned generally along one side of the blade so that the width of the blade obstructs a portion of the alignment marker and the unobstructed portion of the alignment marker identifies the location where at least one side of the blade will engage the workpiece.

14. The apparatus of claim 1 wherein the light projection means is located proximate the front portion of the cutting means.

15. The apparatus of claim 1 wherein the cutting means includes an upper guard and the light projection means is located within the upper guard.

16. The apparatus of claim 15 wherein the light projection means is located within the upper guard proximate the front portion of the cutting means.

17. The apparatus of claim 16 wherein the cutting means includes a lower guard with a front portion and a rear portion located generally between the cutting means and the turntable, the front portion of the lower guard having a slit opening through which the optical alignment marker may be projected onto the workpiece.

18. A miter saw with an optical system for projecting an optical alignment marker onto a workpiece, comprising:

a base;

a turntable rotatably supported by the base, the turntable having a front and rear portion;

a fence disposed above the base for supporting the orientation of the workpiece located on the base;

a support coupled to the rear portion of the turntable

cutting means including a blade for cutting the workpiece, the cutting means being pivotally coupled to the support for positioning the blade from a raised position above the workpiece to an operational position for engagement with the workpiece, the blade having a radius, a first side, a second side, and a width and the cutting means having a front and rear portion; and

light projection means attached to the cutting means for projecting a planarbeam of light past either the first or the second side of the blade and onto the workpiece in order to form a linear alignment marker on the workpiece along a selected side of the blade, the linear optical alignment marker having a thickness and two sides, the light projection means further comprising adjustment means for selectably adjusting the alignment marker so that the side of the alignment marker facing the selected side of the blade is coincident with a plane defined by the selected side of the blade, whereby the side of the linear optical alignment marker that is coincident with the plane defined by the selected side of the blade will designate the location at which the selected side of the blade will enter the workpiece.

19. A miter saw with an optical system for projecting an optical alignment marker onto a workpiece, comprising:

a base;

a turntable rotatably supported by the base, the turntable having a front and rear portion;

a fence disposed above the base for supporting the orientation of the workpiece located on the base;

a support coupled to the rear portion of the turntable;

cutting means including a blade for cutting the workpiece, the cutting means being pivotally coupled to the support for positioning the blade from a raised position above the workpiece to an operational position for engagement with the workpiece, the blade having a radius, two sides, and a width and the cutting means having a front and rear portion; and

light projection means attached to the cutting means for projecting a beam of light past at least one side of the blade and onto the workpiece in order to form an optical alignment marker on the workpiece, the alignment marker facing the at least one side of the blade, the light projection means further comprising adjustment means for adjusting the beam of light so that a particular portion of the alignment marker is coincident with a plane defined by one side of the blade, whereby the location of the particular portion of the alignment marker that is coincident with the plane defined by the one side of the blade designates the location at which the one side of the blade will enter the workpiece.