HK1092767B - Builder's measuring and marking tool - Google Patents

Description

Builder's measuring and marking tool

RELATED APPLICATIONS

In accordance with 35 § 119 (e) of united states code, the present application claims priority from united states provisional patent application No.60/453099, filed 3, 7, 2003, which is expressly incorporated herein by reference.

Technical Field

The present invention relates to the field of measuring and marking tools, and in particular to a builder's measuring and marking tool, such as a roofing square for roofing or construction framework.

Background

Various triangular roofing squares are known for use in basic roof construction. This allows carpenters to measure and cut different types of rafters for building roofs, including common rafters and hip and valley rafters. For example, known roofing squares allow a user to mark hip and valley plumb tangents using only one measurement scale, such as a scale of unit increment value.

In addition, known roofing squares enable a carpenter to mark a level line or base cut on a rafter by aligning a characteristic feature of the square with a plumb line, wherein the only purpose of the feature is to make the base cut. If other structures for performing different functions are added to the square, it may be necessary to change the location and configuration of the base cutout feature. This adversely affects the utility of the base cut feature because it makes it more difficult for a carpenter to accurately align the feature with the plumb line.

Thus, there remains a need for a roofing square that has a simple and effective means of marking different types of cuts to rafters used to construct a roof.

Disclosure of Invention

In one aspect of the invention, a builder's measuring and marking tool is provided. The tool includes a planar member having a right triangle configuration including a first side edge, a second side edge extending orthogonal to the first side edge, and a third side edge intersecting the first and second side edges to form a hypotenuse of the right triangle configuration. The tool also includes an elongated aperture spaced inwardly from the third side edge and bounded by at least one straight edge parallel to the third side edge. The tool also includes first hip and valley marking indicia formed along at least one straight edge of the elongated aperture. In addition, the tool includes an aperture having a first inner side edge parallel to the at least one straight edge of the elongated aperture, and second hip and valley marking indicia formed along the first inner side edge.

In another aspect of the invention, a builder's measuring and marking tool is also provided. The tool includes a planar member having a right triangle configuration including a first side edge, a second side edge extending orthogonal to the first side edge, and a third side edge intersecting the first and second side edges to form a hypotenuse of the right triangle configuration. The tool also includes an elongated aperture spaced inwardly from the third side edge and bounded by opposing straight edges parallel to the third side edge. The tool also includes a scribe bar spaced inwardly from the second side edge and having at least one scribing edge parallel to the second side edge. The scribing edge includes at least one notch at a predetermined distance from the first side edge. In addition, the tool comprises an aperture in the form of a right triangle having a first inner side edge intersecting a second inner side edge at a right angle, and a third inner side edge representing the hypotenuse of the right triangle aperture. The third inner side edge is parallel to the opposite straight edge of the elongated aperture.

In another aspect of the invention, a builder's measuring and marking tool is also provided. The tool includes a planar member having a right triangle configuration including a first side edge, a second side edge extending orthogonal to the first side edge, and a third side edge intersecting the first and second side edges to form a hypotenuse of the right triangle configuration. The intersection of the first and second side edges defines a pivot point. The tool further comprises abutment means along the first side edge for abutting against the workpiece when the second side edge is positioned to extend over the workpiece. The tool further includes a distance marking indicia formed along the second side edge for marking a distance from the first side edge, including a predetermined distance corresponding to a standard width of a piece of wood. The tool also includes an angle marking indicia formed along the third side edge for marking an angle and for marking an angle measurement for a common rafter plumb line. The tool also includes a scribe bar spaced inwardly from the second side edge. The scribe bar has at least one scribe edge parallel to the second side edge. The scribing edge includes at least one score located a predetermined distance from the first side edge corresponding to a standard width of a piece of wood. The tool also includes an elongated aperture spaced inwardly from the third side edge and bounded by opposing straight edges parallel to the third side edge. The tool also includes a common rafter marking indicia formed along the first straight edge of the elongated aperture for marking a unit increment measurement for a common rafter plumb line. The tool also includes first hip and valley marking indicia formed along the second straight edge of the elongated aperture for marking a unit increment or angular measurement for the hip and valley rafter plumb lines. The tool further comprises an aperture in the form of a right triangle having a first inner side edge intersecting a second inner side edge at a right angle and a third inner side edge representing the hypotenuse of the right triangle aperture. The third inner side edge is parallel to the opposite straight edge of the elongated aperture. The tool further comprises second hip and valley marking indicia formed along the third inner side edge for marking any unit increments or angular measures not marked with the first hip and valley marking indicia. The tool also includes a linear scribe mark formed along the first inner side edge indicating a distance from the second side edge.

In another aspect of the invention, a method of scribing a pedestal cut on a workpiece using a builder's measuring and scribing tool is provided. The tool includes a planar member having a right triangle configuration, the planar member including a first side edge, a second side edge extending orthogonal to the first side edge, an abutment means along the first side edge, a distance marking indicia formed along the second side edge for marking a distance from the first side edge including a predetermined distance corresponding to a standard width of a piece of wood, and a scribe bar spaced inwardly from the second side edge and having at least one scribe edge parallel to the second side edge, the scribe edge including at least one score disposed a predetermined distance from the first side edge. The method comprises drawing a plumb line on a workpiece; placing the builder's measuring and marking tool on the workpiece with the abutment device along a side edge of the workpiece; sliding a measurement and marking tool of a builder along a side edge of the workpiece until a distance marking mark for marking a predetermined distance is overlapped on the vertical line; pivoting the builder's measuring and marking tool about a pivot point defined by the intersection of the first and second side edges until the plumb line intersects both the distance marking indicia for marking a predetermined distance and the scribe bar score disposed a predetermined distance from the first side edge; and drawing a base cut line along the second straight edge of the tool from the plumb line to a side edge of the workpiece.

Drawings

FIG. 1 is a plan view of a builder's measuring and marking tool according to the present invention;

FIG. 2 is a partial front view of the builder's measuring and marking tool of FIG. 1;

FIG. 3 shows a base cut-out or socket on a common rafter;

FIG. 4 is a perspective view of the builder's measuring and marking tool of FIG. 1 used to mark plumb lines on common rafters; and

fig. 5 is a perspective view of the builder's measuring and marking tool of fig. 1 used to mark a base cut or a birdsmouth on a common rafter.

Detailed Description

A builder's measuring and marking tool 2 according to the present invention is shown in figures 1 and 2. The exemplary tool 2 is provided with various marking indicia specifying metric units of measurement. However, it will be readily appreciated that the metric scale may not only be a measurement scale for practicing the present invention, but that the tool 2 may employ scribe marks that specify other units of measurement, such as english inch units of measurement.

As shown in FIG. 1, the builder's measuring and marking tool 2 includes a planar member 4 having a right triangle perimeter configuration, sometimes referred to as a roofing square, which includes a first side edge 6 having a first end 8, the first end 8 intersecting a second side edge 10 at a first end 12 thereof at a right angle, thereby forming a pivot point 9. The planar member 4 also has a third side 14 with opposite ends 16 and 20 which forms the hypotenuse of the right triangle tool 2. The third side 14 intersects the first side 6 at its opposite end 18 at one end 16 and the second side 10 at its opposite end 22 at the opposite end 20.

The measuring and marking tool 2 has a first planar surface 24 facing in one direction and a second planar surface 26 facing in the opposite direction, which surfaces are parallel to each other and spaced apart by a distance of, for example, three sixteenths to one quarter of an inch, as shown in fig. 2. A first smooth straight-sided wall surface 28 extends between these planar surfaces along the second side edge 10 to provide a scoring edge along which a pencil can be drawn to draw a smooth straight line. A second smooth straight-sided wall surface 30 extends between these planar surfaces along the third side edge 14 to provide a smooth scoring edge also along that side of the tool 2.

As shown in FIG. 2, a T-bar 32 is provided along the first side edge 6, the T-bar 32 having a first projection 34 with a planar surface extending outwardly a short distance of about one-quarter inch and orthogonal to the first planar surface 24 facing inwardly therefrom, the T-bar 32 also having a second projection 36 with a planar surface extending outwardly a short distance of about one-quarter inch and orthogonal to the second oppositely facing planar surface 26 facing inwardly therefrom. The T-bar 32 has an oppositely facing planar surface 38 that faces outwardly and away from the tool 2. These dimensions for the first and second projections 34 and 36 are merely illustrative and are not meant to be limiting. Those skilled in the art will readily recognize that the T-bar 32 may have other dimensions and that other projections, lips or flanges may be used as abutment means in place of the projection 34 or 36 to provide a stop against which the first side edge 6 may rest.

Referring now to fig. 1, the second side edge 10 has distance marking indicia 40 therealong, which begins at end 12 adjacent end 8 of the first side edge 6. In this embodiment, distance marking indicia 40 are formed on the first and second planar surfaces 24, 26 in increments of one-half centimeter and with a number to show each successive centimeter, starting with the number 1 to represent the first centimeter away from the end 8 of the first side edge 6.

The hypotenuse or third side edge 14 has an angle marking indicia 42 formed therealong on the first planar surface 24 and the second planar surface 26. In this embodiment, the angle marking indicia 42 define an angle scale beginning at the end 16 of the third side adjacent the end 18 of the first side 6.

The measuring and marking tool 2 according to the present invention further includes a marking bar 44 disposed parallel to the second side edge 10 and spaced inwardly therefrom by a distance of, for example, five eighths of an inch. The scribe bar 44 is bounded by parallel scribe edges 44a and 44b, each having a score 46 corresponding to the distance scribe marks 40 formed along the second side edge 10. In this embodiment, successive scores 46 are provided alternately between the scoring edges 44a and 44b to define one-half centimeter increments between successive scores 46. This configuration also defines one centimeter increments between adjacent scores 46 formed in either of the score edges 44a and 44 b. The scribe bar 44 includes a score 46a corresponding to the scribe mark 40a formed at a distance of ten and one-half centimeters or the standard metric width of a piece of wood or timber from the end 8 of the first side edge 6.

The measuring and marking tool 2 according to the present invention further comprises an elongated aperture 50 bounded by parallel straight edges 52 and 54. The holes are parallel to the hypotenuse or third side 14 of the square 2 and are spaced inwardly therefrom, for example, by a distance of about one and one quarter inches. First hip and valley marking indicia 58 are formed on first planar surface 24 and second planar surface 26 along straight edge 52 of elongated aperture 50. In the present embodiment, for example, the first hip and valley marking indicia 58 define an angular scale for measuring plumb lines for hip and valley rafters.

Common rafter marking indicia 56 are formed on first planar surface 24 and second planar surface 26 along straight edges 54 of elongated apertures 50 to measure plumb lines for the common rafters. In this embodiment, for example, common rafter marking indicia 56 define a scale of unit increment values corresponding to an increment value in centimeters per 10 centimeter of horizontal rafter extension.

The measuring and marking tool 2 further comprises a generally triangular aperture 60 in the form of a right triangle having a second inner side edge 64 which intersects the first inner side edge 62 at a right angle, and a third inner side edge 66 which represents a hypotenuse. The beveled or third inner side edge 66 is parallel to the straight edges 52 and 54 of the elongated aperture 50 and is spaced from the straight edge 54 by a distance of, for example, about three-quarters of an inch. The first inner side edge 62 of the triangular aperture 60 is parallel to the first inner side edge 6 of the tool 2 and spaced inwardly therefrom by a distance of, for example, about five eighths of an inch. The second inner side edge 64 of the triangular aperture 60 is parallel to the second side edge 10 of the tool 2 and spaced inwardly therefrom by a distance of, for example, about two inches. In particular, the second inner side edge 64 may be spaced inwardly from the second side edge 10 by a distance corresponding to the size of a standard metric stud used for a piece of lumber or timber. Additionally, the scribing edge 44a of the scribing rod 44 may be spaced inwardly from the second side edge 10 by a distance corresponding to one-half of a standard metric post size for a piece of lumber or timber.

Second hip and valley marking indicia 68 are formed on the first planar surface 24 and the second planar surface 26 along a third inner side edge 66 representing the hypotenuse of the triangular aperture 60 for measuring plumb lines for hip and valley rafters. In this embodiment, the second hip and valley marking indicia 68 define a scale that is different from the first hip and valley marking indicia 58, such as a scale corresponding to increments in centimeters per about 14 centimeters of horizontal rafter extension. Notches 70 and 72 are preferably formed at the ends of the hypotenuse or third inner side edge 66 that intersect the first and second inner side edges 62 and 64, respectively, to allow a user to mark measurements for hip and valley rafters using the second hip and valley marking indicia 68 formed thereon proximate the end of the third inner side edge 66.

A straight line marking indicia 74 is formed on the opposed planar surfaces 24 and 26 of the square 2 along the first inner side edge 62 of the triangular aperture 60 starting with indicia representing the distance from the second side edge 10 of the tool 2 along the inner side edge 62. In this embodiment, for example, the linear scribe marks 74 are formed in one centimeter increments and are numbered to show each successive centimeter, starting with the number 6 to represent the sixth centimeter away from the second side edge 10.

One application of the measuring and marking tool 2 according to the present invention is described for marking triangular base cuts in pieces of timber or timber used as common rafters, these base cuts being commonly referred to commercially as sockets. These sockets are cut-outs for receiving and bearing against the ridge plate of the building wall when the common rafter is placed in position to project obliquely upwardly from the ridge plate of the building wall at the desired angle. Fig. 3 shows a socket 106 for the workpiece 102. One side of the socket 106 extends vertically to abut the vertical side wall of the ridge plate and the other side of the socket extends horizontally and abuts the upwardly facing horizontally extending surface of the ridge plate.

First, a plumb line 100 is drawn on a workpiece 102 to make a common rafter, as shown in fig. 4. In this case the plumb line 100 represents vertical when the common rafter is in place. To scribe the plumb line 100, the user places the tool 2 on the workpiece 102, wherein the T-bar 32 is pressed along the side edge 104 of the workpiece 102, and slides the tool to a desired position on the workpiece. The tool is rotated about pivot point 9 so that the end 18 of the first side edge 6 moves away from the side edge 104 of the workpiece 102 until the desired unit increment measurement of the common rafter marking indicia 56 is aligned with the side edge 104. Alternatively, the user may move the tool away from the side edge 104 until the desired angular measure of the angular scribe marks 42 is aligned with the side edge 104. A common rafter plumb line 100 is drawn along the second side edge 10 of the tool 2.

The tool 2 is then rotated onto its opposite planar surface and the workpiece 102 is placed with the T-bar 32 pressed along the side 104 of the workpiece 102 in which the birdsmouth 106 is to be cut. The second side edge 10 of the square 2 extends inwardly of the workpiece with the ten and one-half cm of marking indicia 40a from the marking indicia 40 positioned inwardly a distance corresponding to one ten and one-half cm of the standard metric width of a piece of timber or timber. The user slides the tool 2 along the edge 104 of the workpiece 102 until the ten and one-half centimeter marking indicia 40a overlap the plumb line 100. The square 2 is then rotated about the pivot point 9 with the ten and one-half cm score mark 40a above the plumb line 100 until the plumb line 100 intersects the ten and one-half cm score mark 40a and the corresponding score 46a of the score bar 44, as shown in figure 5.

When the square 2 is pivoted to this position, the second side edge 10 extends at a right angle to the plumb line 100. A cut-out line 108 is then drawn along the second side edge 10 from the plumb line 100 to the edge 104 of the workpiece 102. The cut line 108 extends at right angles to the plumb line 100. A birdsmouth 106 is then cut out on the cut-out line 108 and on the plumb line 100 from the edge 104 of the workpiece 102 to its intersection with the cut-out line 108 as shown in fig. 5. In doing so, when the common rafter extends therefrom at the desired angle in its correct diagonal position, the portion of the birdsmouth 106 along the plumb line 100 will abut vertically with the vertical side of the ridge plate and the portion of the cut along the cut line 108 will abut horizontally on the horizontal plane of the ridge plate.

Another application of the described measuring and marking tool 2 according to the present invention is the use of the first and second hip and valley marking indicia 58 and 68 for marking plumb lines for hip rafters and valley rafters. In particular, the tool 2 is placed on the workpiece while the T-bar 32 is pressed along the side edge of the workpiece. The tool 2 is pivoted about the pivot point 9 so that the end 18 of the first side edge 6 is moved away from the side edge of the workpiece until the desired unit increment measurement of the second hip and valley marking indicia 68 is aligned with the side edge of the workpiece or the desired angular measurement of the first hip and valley marking indicia 58 is aligned with the side edge of the workpiece. A ridge and groove plumb line is drawn on the workpiece along the second side edge 10 of the tool 2.

The measuring and marking tool 2 according to the present invention as described may also be used to scribe a line perpendicular to the edge of the workpiece or a line parallel to the edge of the workpiece. In particular, the tool 2 is placed on the workpiece while the T-bar 32 is pressed along the side edge of the workpiece. To draw a vertical line, the user draws a line on the workpiece along the second side edge 10 of the tool 2. To mark a parallel line, the user places a pencil in the score 46 of the scribe bar 44 and slides the tool 2 along the side edge of the workpiece while pressing the T-bar 32 all the way along the side edge.

In addition, the measuring and marking tool 2 according to the present invention may be used to mark a pair of lines perpendicular to the edge of a workpiece, such as a floor, that correspond to standard stud sizes for a piece of timber or lumber. In particular, the tool 2 is placed on the workpiece while the T-bar 32 is pressed along the side edge of the workpiece. The user then draws a first line on the workpiece along the second side edge 10 of the tool 2 and a second line on the workpiece along the second inner side edge 64 of the triangular aperture 60. The first and second lines depict the location of the strut member on the workpiece. The user can also scribe a center line for the pillar member by drawing a line on the workpiece along the scribing edge 44a of the scribing bar 44.

In addition, the measuring and marking tool 2 according to the present invention as described may be used as a saw guide. For example, the user may place the tool 2 on a work piece in the manner described above while pressing the pivot point 9 along the side edge of the work piece for marking plumb lines for common rafters or for hip rafters and valley rafters. The user may then run the saw along the side edge 10 of the tool 2 to make the desired cut to the workpiece. Those skilled in the art will recognize that the tool 2 may be used as a protractor for drawing or measuring different angles using the angle scribe marks 42 formed along the hypotenuse or third side 14 of the tool, and also as an angle gauge for aligning a workpiece at 90 degree angles and 45 degree angles.

Although the present invention has been described and illustrated with reference to specific exemplary embodiments thereof, the present invention is not limited to these exemplary embodiments. Those skilled in the art will recognize that variations and modifications can be made without departing from the true scope and spirit of the invention as defined by the appended claims. It is therefore intended to include within the invention all such variations and modifications as fall within the scope of the appended claims and equivalents thereof.

Claims (13)

1. A builder's measuring and marking tool comprising:

a planar member including a first side, a second side extending orthogonal to the first side, and a third side intersecting the first and second sides to form a hypotenuse of the right triangle configuration;

an elongated aperture spaced inwardly from the third side edge and bounded by at least one straight edge parallel to the third side edge;

first ridge and valley marking indicia formed along at least one straight edge of the elongated aperture;

an aperture having a first inner side edge parallel to at least one straight edge of the elongated aperture; and the number of the first and second electrodes,

wherein the tool further comprises a second hip and valley marking indicia formed along the first inner side edge.

2. The builder's measuring and marking tool as recited in claim 1, further comprising a common rafter marking indicia measured in unit increments of measurement formed along the second straight edge of the elongated aperture.

3. The builder's measuring and marking tool as defined in claim 2, wherein the first hip and valley marking indicia is measured in one of a unit increment and an angular measure, and the second hip and valley marking indicia is measured in one of the unit increment and the angular measure that is not marked with the first hip and valley marking indicia.

4. The builder's measuring and marking tool as claimed in claim 2, further comprising abutment means along the first side edge for abutting against a work piece when the second side edge is disposed to extend over the work piece.

5. The builder's measuring and marking tool as claimed in claim 2, wherein the measuring and marking tool further comprises a distance marking indicia formed along the second side edge for marking a distance from the first side edge, including a predetermined distance corresponding to a standard width of a piece of wood.

6. The builder's measuring and marking tool as claimed in claim 2, further comprising angle marking indicia formed along the third side edge for marking angles and for marking angle measurements for common rafter plumbs.

7. The builder's measuring and marking tool as claimed in claim 5, further comprising a marking bar spaced inwardly from the second side edge and having at least one marking edge parallel to the second side edge, the at least one marking edge including at least one indentation at the predetermined distance from the first side edge.

8. The builder's measuring and marking tool as claimed in claim 1, wherein the aperture further comprises a second inner side edge parallel to the first side edge of the planar member, and a linear marking indicia formed along the second inner side edge representing a distance from the second side edge of the planar member.

9. The builder's measuring and marking tool as claimed in claim 8, wherein the aperture further comprises a third inner side edge parallel to the second side edge of the planar member and spaced inwardly from the second side edge by a predetermined distance corresponding to a standard size for a stanchion.

10. The builder's measuring and marking tool as claimed in claim 8, wherein the marking bar has at least one marking edge spaced inwardly from the second side edge by a predetermined distance corresponding to half the standard size for a post.

11. A builder's measuring and marking tool comprising:

a planar member having a right triangle configuration, the planar member including a first side, a second side extending orthogonal to the first side, and a third side intersecting the first and second sides to form a hypotenuse of the right triangle configuration;

an elongated aperture spaced inwardly from the third side edge and bounded by opposing straight edges parallel to the third side edge;

first ridge and valley marking indicia formed along at least one straight edge of the elongated aperture;

a second hip and valley marking indicia formed along the first inner side edge;

a scribe bar spaced inwardly from the second side edge and having at least one scribing edge parallel to the second side edge, the at least one scribing edge including at least one score from the first side edge at a predetermined distance corresponding to a standard width of a piece of wood; and

an aperture in the form of a right triangle having a first inner side edge intersecting the second inner side edge at a right angle, and a third inner side edge representing the hypotenuse of the right triangle, the third inner side edge being parallel to the opposing straight edge of the elongated aperture.

12. A builder's measuring and marking tool comprising:

a planar member having a right triangle configuration, the planar member including a first side, a second side extending orthogonal to the first side, and a third side intersecting the first and second sides to form a hypotenuse of the right triangle configuration, wherein an intersection of the first and second sides defines a pivot point;

abutment means along said first side for abutting against a workpiece when said second side is positioned to extend over said workpiece;

a distance marking mark formed along the second side edge for marking a distance from the first side edge, including a predetermined distance corresponding to a standard width of a piece of wood;

an angle marking indicia formed along the third side edge for marking an angle and for marking an angle measure for a common rafter plumb line;

a score bar spaced inwardly from the second side edge, the score bar having at least one score edge parallel to the second side edge, the at least one score edge including at least one score located the predetermined distance from the first side edge;

an elongated aperture spaced inwardly from the third side edge and bounded by opposing straight edges parallel to the third side edge;

common rafter marking indicia formed along a first straight edge of the elongated aperture for marking a unit incremental measurement for a common rafter plumb line;

first hip and valley marking indicia formed along a second straight edge of the elongated aperture for marking unit increments and angular measurements for hip and valley rafter plumb lines;

an aperture in the form of a right triangle having a first inner side edge intersecting a second inner side edge at a right angle and a third inner side edge representing a hypotenuse of the right triangle, the third inner side edge being parallel to the opposing straight edges of the elongated aperture;

second hip and valley marking indicia formed along said third inner side edge for marking one of said unit increments and said angular measure not marked with first hip and valley marking indicia; and

a linear scribe mark formed along a first inner side edge representing a distance from the second side edge.

13. A method of scribing a pedestal cut on a workpiece using a builder's measuring and scribing tool, the tool comprising: a planar member having a right triangle configuration, the planar member including a first side, a second side extending orthogonal to the first side, and a third side intersecting the first and second sides to form a hypotenuse of the right triangle configuration; an elongated aperture spaced inwardly from the third side edge and bounded by at least one straight edge parallel to the third side edge; first ridge and valley marking indicia formed along at least one straight edge of the elongated aperture; a second hip and valley marking indicia formed along the first inner side edge; abutment means along said first side edge; a distance marking mark formed along the second side edge for marking a distance from the first side edge, including a predetermined distance corresponding to a standard width of a piece of wood; and a scribe bar spaced inwardly from the second side edge and having at least one scribing edge parallel to the second side edge, the at least one scribing edge including at least one score disposed at the predetermined distance from the first side edge, the method comprising:

drawing a plumb line on the workpiece;

placing the builder's measuring and marking tool on the workpiece with the abutment device along a side of the workpiece;

sliding the builder's measuring and marking tool along the side of the workpiece until the distance marking indicia for marking out the predetermined distance is superimposed on the plumb line;

pivoting the builder's measuring and marking tool about a pivot point defined by the intersection of the first and second side edges until the plumb line intersects both the distance marking indicia for marking the predetermined distance and the at least one score of the line bar disposed at the predetermined distance from the first side edge; and

drawing a base cut line along the second straight edge of the tool from the plumb line to the side edge of the workpiece.