GB2309006A - Saw blade - Google Patents

Abstract

A saw blade has radially spaced indicia on at least one of the faces to provide a direct indication of the protrusion of the blade from a table of a saw. The indicia are at predetermined distances from the cutting edge of the blade and may be in the form of visibly distinct concentric rings or a section of a rule 34 extending radially.

Description

Title: SAW BLADE The present invention relates to saw blades and in particular to blades intended for circular saws.

Circular saws are used in a variety of applications and conventionally utilize a spindle powered Dy rl electric motor and a table over which the workpiece rnove. The spacing betueen the spindle and table may be adjusted to provide different depths of cut for the material passing over the table.

In the case of a fixed table saw, the table is typically mounted upon a base and the spindle adjusted relative to the base. ch a portable saw, the motor and spindle are mounted in a saw housing and the table pivoted to that housing to allow adjustment of the depth of cut when adjusting for depths of cut, it is conventional to utilize a tape to measure the protrusion of the saw blade above the table. With larger tables such as those found on commercial table saws, this requires the operator to position the tape against the blade and manipulate the adjusting mechanism at the same irne. On larger table saws, this is not feasible so that it is necessary to repeatedly measure and adjust until the correct depth is achieved.Moreover, the throat tnrough vhich the saw blade passes makes accurate measurement of the protrusion above the table difficult because of the free space next to the saw blade, so it is frequeptly necessary to check the depth of cut once the adj ustment has been made.

It is therefore an object of the present Invention to provide a saw blade in which the above disadvantages are obviated or mitigated.

In general terms, therefore, the present invent on provides a saw blade having 2 pair of opposed radially extending faces terminating in 2 peripheral jutting edge. At least one of the faces bears radially spaced indicia corresponding to predetermined distances from the cutting edge. In this manner, the protrusion of the blade above the table may readily be determined by sighting the indicia relative to the table and adjustments made.

Preferably the indicia are distinguishable from one another and preferably are concentric circles imprinted upon each face of the blade tc provide continuous indication.

It is also preferred that the indicia are such that they are visible while the blade is rotating.

If preferred, different spacings may be printed on opposite faces such;that one face may include indicia in imperial spacing whereas another may include indicia in metric.

An embodiment of the invention will now be described by way of exampl-e only with reference to the accompanying drawings, in which Figure 1 is a perspective view of a table saw; Figure 2 is a view on the line 2-2 of Figure 1; Figure 3 is a view in the direction of arrow III of Figure 2; and Figure 4 is an enlarged view of a portion of the blade shown in Figure 3.

Referring therefore to Figure 1, a table saw generally indicated at 10 includes a table 12 and a base 14. Located in the base is a motor (not shown) operatively connected to a spindle 16 to rotate about a generally horizontal axis. The table 12 includes a throat 18 through which a blade 20 projects.

The spindle 16 and therefore the blade 20 may be adjusted in a vertical direction in a well-known manner relative to the table 12 to adjust the projection of the edge 28 above the table and therefore the cutting depth of the blade 20.

As can best be seen in Figure 2, blade 20 has a pair of oppositely directed faces 22,24 and a central mounting bore 26 to receive the spindle 16. The periphery of the blade 20 is formed with a serrated cutting edge 28 with adjacent teeth of the serrations offset from one another to provide an adequate kerf in the material being cst for the blade 20 to pass.

Each of the faces 22,2 is imprinted with concentric circular bands indicated generically at 32.

The bands 32 are spaced at predetermined distances from the edge 28 and, as indicated in Figure 4, may be differentiated from one another by varying line thicknesses and types. Thus, as seen in Figure 4, the line 32a is of double thickness and indicates an integral number of inches from the periphery 28. The spacing between lines 32b,32c,32d and 32e is each one-quarter inch with the line 332c being formed as a double line indicating a half-inch on the lines 325 and 32d formed as a single fine. line indicating a one-quarter and three-quarter inch increment respectively.

The opposite face 24 may bear indicia spaced in metric intervals and distinguished from one another in a similar manner.

A radial rule 34 is imprinted on the face with measurements starting at the edge 28 to provide finer graduations and absolute measurements. The rule 34 may be imprinted at several locations circumferentially spaced if preferred to ensure that at least one rule is in the sector above the table and can be observed whenever the blade is stationary.

In operation, therefore, the spindle 16 maybe adjusted vertically with the blade stationary until the appropriate one of the lines 32 is flush with the plane of the table top 12. In that position, the operator is confident that the projection of the peripheral edge 28 is a set distance above the height of the table 12.

In the event that subsequent adjustment is required after a trail cut, the degree of adjustment is readily discernible from the spacing between the adjacent lines 32 so that an incremental adjustment may be made either with the blade stationary or with it rotating.

The spacing of the lines 32 from the peripheral edge will of course vary as the peripheral edge 28 wears but the utilization of carbide tip saws reduces the wear on the tip so that the difference in diameter is indiscernible.

Similar considerations of course apply if the blade is utilized in a portabie saw where the discernible indicia provide a ready indication of the depth of cut without requiring measurement with a tape which may not be convenient in many locations.

As can be seen in Figure 4, the bands 32 are interrupted at one or more locations and a numeral indicating the nominal distance from the edge 28 imprinted to provide a visual reference. The banks 32 may of course be formed as sectors rather than the full circumference so that additional information can be carried on the faces 22,24.

Claims (9)

1. A saw blade having a pair of oppositely directed radially extending faces terminating in a peripheral cutting edge, at least one of said faces bearing radial r spaced indicia corresponaing to predetermined radial distances from said cutting edge.

2. A saw blade according to claim 1 wherein adjacent indicia are visually distinguishable from one another.

3. A saw blade according to claim 1 or 2 wherein said indicia are concentric circles imprinted upon said one face.

4. A saw blade according to any preceding claim wherein each of said faces bears indicia.

5. A saw blade according to claim 4 wherein indicia on one of said faces are spaced at intervals corresponding to an Imperial measuring system and indicia on another of said faces are spaced at intervals corresponding to a metric measuring system.

6. A saw blade according to any one of claims 1,3 and 5 wherein a rule is imprinted upon one of said faces and extends radially from said peripheral edge.

7. A saw blade according to claim 6 wherein a plurality of circumferentially spaced rules are imprinted upon said one face.

8. A saw blade according to any one of claims 1, 3 and 4 wherein said indicia are visible during rotation of said blade.

9. Any novel feature or combination of features disclosed herein.