Improved carpenter tool

Abstract

A carpenter angle square (410) includes a body (11) including first, second and third edges (13, 14, 15). The guide plate (411) is pivoted to the first edge (13) to move among first, second and third positions. In the first and second positions, the guide plate (411) is orthogonal to the body (11). In the third position, the guide plate (411) is coplanar with the body (11). The hinge assembly (440) pivots the guide plate (411) to the body (11) and includes a notch (441) in the body (11), a notch (447) in the notch (441), and a tab (445) projecting from the guide plate (411) and fitting on the pin (453) for reciprocating and rocking movement. The tab (445) moves between a neutral position in which the tab (445) is offset from the notch (447) and disables the guide plate (411) from moving among the first, second and third positions, and an advanced position in which the tab (445) is registered with the notch (447) and enables the guide plate (411) to move among the first, second and third positions.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a continuation-in-part application of and claims the benefit of prior U.S. patent application No. 17 / 715,460 filed on April 7, 2022, and this application also claims the benefit of U.S. Provisional Application No. 63 / 442,110 filed on January 30, 2023, the entire texts of all of the aforementioned applications are hereby incorporated by reference. Technical Field

[0003] This specification relates generally to hand tools, and more particularly to carpenter's squares. Background Art

[0004] Carpenters and other craftsmen use a variety of tools in their trade. Some tools are designed specifically for specific jobs, while other tools are useful in a wide range of applications. One frequently used tool is the carpenter's square or carpenter square.

[0005] Traditionally, a carpenter's square is a triangular piece of plastic or metal with two short sides extending from a right angle and a longer hypotenuse between the two short sides. One of the short sides has a fence, which is a length of material fixed to the side but aligned orthogonal to the body of the square. Thus, the fences protrude outward from both sides of the square, which makes it very easy to place the square against a straight edge of a workpiece and draw a line at right angles to the straight edge.

[0006] The carpenter's square is an important tool in any craftsman's bag. However, all tools are subject to improvement, and the carpenter's square has undergone relatively few and minor changes since its introduction. Improvements to the carpenter's square are needed. Summary of the invention

[0007] According to embodiments described herein, a carpenter's square includes a triangular body having a first edge, a second edge, and a third edge, wherein the first, second, and third edges cooperate to define a perimeter edge of the triangular body. A guide plate is pivotally connected to the first edge to move among first, second, and third positions. In the first position, the guide plate is orthogonal to the triangular body in a first direction. In the second position, the guide plate is orthogonal to the triangular body in a second direction opposite to the first direction. In the third position, the guide plate is coplanar with the triangular body.

[0008] In an embodiment, the triangular body includes opposing first and second body faces, and the guide plate includes opposing first and second guide plate faces. In the third position, the first body face and the first guide plate face are coplanar with each other, and the second body face and the second guide plate face are coplanar with each other. In an embodiment, the carpenter's square includes: a first set of measurements along the second edge, the first set of measurements corresponding to a first zero position offset from the first edge; and a second set of measurements along the second edge, the second set of measurements corresponding to a second zero position offset from the first zero position. In an embodiment, the guide plate is mounted to the triangular body at a hinge assembly, and the hinge assembly includes a notch in the triangular body. A tab protrudes from the guide plate and is mounted in the notch to rock relative to the triangular body within the notch between three positions corresponding to the first, second and third positions of the guide plate. In an embodiment, the tab moves between a neutral position, in which the tab is toward a side of the notch, and an advanced position, in which the tab is away from the side of the notch. The neutral posture of the tab disables the guide plate from moving among the first, second, and third positions, and the advanced posture of the tab enables the guide plate to move among the first, second, and third positions.

[0009] In an embodiment, the guide plate is mounted to the triangular body at a hinge assembly, and the hinge assembly includes a notch in the triangular body, a pin mounted in the notch, a groove formed into the body communicating with the notch, a tab protruding from the guide plate and mounted on the pin for rocking movement within the notch, and a tongue on the tab complementary to the groove. The tab moves between a neutral position, in which the tab faces the side of the notch and the tongue is received in the groove, and an advanced position, in which the tab is away from the side of the notch and the tongue is removed from the groove. A spring biases the tab toward the neutral position. In an embodiment, a jig block carried in the triangular body is removable therefrom and applicable to a face thereof, wherein when the jig block is applied to the face and an edge of the jig block is placed against an edge of a workpiece, the first and second edges of the carpenter's square overlie the workpiece and define cutting lines corresponding to rise and run lines of a stair stringer. In an embodiment, a slot is formed through the triangular body and the jig block is configured to be fixed in position along the length of the slot.

[0010] In an embodiment, the carpenter's square comprises a bubble level having a closed sidewall defining first, second and third sections in fluid communication with each other and a float within the closed sidewall for indicating angle measurement, the float being freely movable between the first, second and third sections. The first section is parallel to one of the first and second edges, the second section is transverse to the first section at a forty-five degree angle, and the third section is transverse to the second section at a forty-five degree angle and orthogonal to the first section. In an embodiment, the carpenter's square comprises a bubble level having a closed sidewall defining first and second tubular sections in fluid communication with each other, a float within the closed sidewall for indicating angle measurement, the float being freely movable between the first section and the second section. The first section is parallel to one of the first and second edges, and the second section is orthogonal to the first section. In an embodiment, the carpenter's square comprises a bubble level having a closed tubular sidewall and a float freely movable within the closed tubular sidewall within the closed tubular sidewall float, the float being used to indicate angle measurements. The closed tubular sidewall is curved in an arc from one end to an opposite end, and horizontal lines are marked on the closed tubular sidewall to indicate zero and ninety degree measurements. In an embodiment, the carpenter's square comprises a bubble level having a container having a disc shape, a perimeter and a top, and a float within the container. Angle measurements are marked along the perimeter such that when the carpenter's square is placed on one of the first, second and third edges, the float rises toward one of the angle measurements. An axis extends above the container and intersects at the top such that when the carpenter's square is placed on a face of its triangular body, the float rises toward the top. In an embodiment, the bubble level comprises an interrupted edge that cuts off the disc shape without interrupting the top of the container.

[0011] In an embodiment, the carpenter's square includes a laser carried in the triangular body and directing a laser beam through an opening in one of the first, second and third edges. In an embodiment, the carpenter's square includes an extension of the triangular body, wherein the extension is a rectangular leg that protrudes continuously along the second edge.

[0012] In an embodiment, the third edge is a bevel edge, the first edge is shorter than the bevel edge, and the second edge is shorter than the bevel edge. In an embodiment, the first edge is a bevel edge, the second edge is shorter than the bevel edge, and the third edge is shorter than the bevel edge. In an embodiment, the second and third edges are joined by diagonal edges defining an open angle of the carpenter's square.

[0013] The above provides the reader with a very brief overview of some embodiments described below. Simplifications and omissions are made, and the overview is not intended to limit or define the present disclosure in any way. Instead, this brief overview merely introduces some aspects of some embodiments to the reader in preparation for the subsequent detailed description.

[0014] According to an embodiment, a carpenter's square includes a body, the body including a first edge, a second edge and a third edge. A guide plate is pivoted to the first edge to move relative to the body in a first, second and third positions. In the first position, the guide plate is orthogonal to the body in a first direction. In the second position, the guide plate is orthogonal to the body in a second direction opposite to the first direction. In the third position, the guide plate is coplanar with the body. A hinge assembly pivots the guide plate to the first edge and includes a notch in the body, a recess in the recess, a pin mounted in the recess, and a tab protruding from the guide plate and mounted on the pin to reciprocate and rock on the pin. The tab moves between a neutral posture and an advanced posture, in which the tab is misaligned with the recess in the recess and the guide plate cannot move among the first, second and third positions, and in which the tab is aligned with the recess in the recess and the guide plate can move among the first, second and third positions.

[0015] In an embodiment, the notch extends from the first edge into the body of the carpenter's square, and the notch further extends from the notch into the body. The tab reciprocates between the neutral position and the advanced position. The guide plate includes a recessed portion, and in the advanced position, the recessed portion is aligned with the first edge so that the first edge can move through the recessed portion when the guide plate moves among the first, second and third positions. In the neutral position, the recessed portion is misaligned with the first edge so that the first edge cannot move through the recessed portion when the guide plate moves among the first, second and third positions. The notch includes a notch face, and the tab includes a first, second and third face. When the guide plate is in the first position and the tab is in the neutral position, the notch face of the notch and the first face of the tab face each other. When the guide plate is in the second position and the tab is in the neutral position, the notch face of the notch and the second face of the tab face each other. When the guide plate is in the third position and the tab is in the neutral position, the notch face of the notch and the third face of the tab face each other. The notch face, first face, second face, and third face are all flat. The guide plate includes an inner edge, and the body of the carpenter's square includes a first face, a second face, and the first edge. When the guide plate is in the first position and the tab is in the neutral position, the inner edge of the guide plate and the second face of the body face each other. When the guide plate is in the second position and the tab is in the neutral position, the inner edge of the guide plate and the first face of the body face each other. When the guide plate is in the third position and the tab is in the neutral position, the inner edge of the guide plate and the first edge of the body face each other. The inner edge, the first face, the second face, and the first edge are all flat.

[0016] According to an embodiment, a carpenter's square includes a body, the body including a first edge, a second edge, a third edge and a guide plate pivoted to the first edge to move relative to the body among first, second and third positions. In the first position, the guide plate is orthogonal to the body in a first direction. In the second position, the guide plate is orthogonal to the body in a second direction opposite to the first direction. In the third position, the guide plate is coplanar with the body. A hinge assembly pivots the guide plate to the first edge and includes a notch in the body and a pin mounted in the notch and a tab protruding from the guide plate and mounted on the pin to reciprocate and rock on the pin in the notch. The tab moves between a neutral posture, in which the tab prevents the guide plate from moving among the first, second and third positions, and an advanced posture, in which the tab enables the guide plate to move among the first, second and third positions.

[0017] In an embodiment, the tab reciprocates between the neutral position and the advanced position. The guide plate includes a recess. In the advanced position, the recess is aligned with the first edge so that the first edge can move through the recess when the guide plate moves among the first, second and third positions. In the neutral position, the recess is misaligned with the first edge so that the first edge cannot move through the recess when the guide plate moves among the first, second and third positions. The notch includes a notch face, and the tab includes a first, second and third face. When the guide plate is in the first position and the tab is in the neutral position, the notch face of the notch and the first face of the tab face each other. When the guide plate is in the second position and the tab is in the neutral position, the notch face of the notch and the second face of the tab face each other. When the guide plate is in the third position and the tab is in the neutral position, the notch face of the notch and the third face of the tab face each other. The notched face, the first face, the second face, and the third face are all flat. The guide plate includes an inner edge, and the body of the carpenter's square includes a first face, a second face, and the first edge. When the guide plate is in the first position and the tab is in the neutral position, the inner edge of the guide plate and the second face of the body face each other. When the guide plate is in the second position and the tab is in the neutral position, the inner edge of the guide plate and the first face of the body face each other. When the guide plate is in the third position and the tab is in the neutral position, the inner edge of the guide plate and the first edge of the body face each other. The inner edge, the first face, the second face, and the first edge are all flat.

[0018] According to an embodiment, a carpenter's square includes a body including a first edge, a second edge, a third edge, and a guide plate pivoted to the first edge to move relative to the body among first, second, and third positions. In the first position, the guide plate is orthogonal to the body in a first direction. In the second position, the guide plate is orthogonal to the body in a second direction opposite to the first direction. In the third position, the guide plate is coplanar with the body. A hinge assembly pivots the guide plate to the first edge and includes a notch in the body, a recess in the notch, a pin mounted in the notch, and a tab protruding from the guide plate and mounted on the pin to reciprocate and rock on the pin in the notch. The tab moves between a neutral posture and an advanced posture, in which the tab is misaligned with the recess and the guide plate cannot move among the first, second, and third positions, and in which the tab is aligned with the recess and the guide plate can move among the first, second, and third positions.

[0019] In an embodiment, the notch extends from the first edge into the body of the carpenter's square, and the notch further extends from the notch into the body. The tab reciprocates between the neutral position and the advanced position. The guide plate includes a recessed portion. In the advanced position, the recessed portion is aligned with the first edge so that the first edge can move through the recessed portion when the guide plate moves among the first, second and third positions. In the neutral position, the recessed portion is misaligned with the first edge so that the first edge cannot move through the recessed portion when the guide plate moves among the first, second and third positions. The notch includes a notch face, and the tab includes a first, second and third face. When the guide plate is in the first position and the tab is in the neutral position, the notch face of the notch and the first face of the tab face each other. When the guide plate is in the second position and the tab is in the neutral position, the notch face of the notch and the second face of the tab face each other. When the guide plate is in the third position and the tab is in the neutral position, the notch face of the notch and the third face of the tab face each other. The notch face, first face, second face, and third face are all flat. The guide plate includes an inner edge, and the body of the carpenter's square includes a first face, a second face, and the first edge. When the guide plate is in the first position and the tab is in the neutral position, the inner edge of the guide plate and the second face of the body face each other. When the guide plate is in the second position and the tab is in the neutral position, the inner edge of the guide plate and the first face of the body face each other. When the guide plate is in the third position and the tab is in the neutral position, the inner edge of the guide plate and the first edge of the body face each other. The inner edge, the first face, the second face, and the first edge are all flat. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Refer to the attached pictures:

[0021] Figure 1A , 1B and 1C are front and perspective views of an embodiment of an improved carpenter's square having a guide plate mounted for rocking movement;

[0022] Figures 2A to 2D yes Figure 1A an enlarged perspective view of the guide plate of the improved carpenter's square showing the guide plate moving between positions;

[0023] Figures 3A to 3C are perspective and plan views of an embodiment of an improved carpenter's square having a jig block for designing a cutting pattern on a workpiece;

[0024] Figure 4 is a perspective view of an embodiment of an improved carpenter's square having a guide plate mounted for rocking movement;

[0025] Figure 5 is a perspective view of an embodiment of an improved carpenter's square having a guide plate mounted for rocking movement;

[0026] Figure 6 It is along Figure 5 A cross-sectional view taken along line 6-6 in FIG. 1 ; and

[0027] Figure 7 is a perspective view of an embodiment of an improved carpenter's square having a guide plate mounted for rocking movement;

[0028] Figure 8 is a perspective view of a modified carpenter's level having round and square bubble levels;

[0029] Fig. 9A yes Figure 8 A magnified view of the circular bubble level;

[0030] Fig. 9B It is along Fig. 9A A cross-sectional view of the circular bubble level taken along line 9-9;

[0031] Fig. 10A yes Figure 8 A magnified view of the square bubble level;

[0032] Fig. 10B It is along the Fig. 10A A cross-sectional view of the square bubble level taken along line 10-10;

[0033] Fig.11A and 11B are front and perspective views of an embodiment of an improved carpenter's square having a guide plate mounted for rocking movement;

[0034] Figures 12A to 12G yes Fig.11A An enlarged perspective view of the guide plate of the improved carpenter's square of FIG. 1 showing the guide plate moving between positions and between attitudes;

[0035] Fig.13A is a front view of an embodiment of an improved carpenter's square having a guide plate mounted for rocking movement;

[0036] Figures 13B to 14E yes Fig.13A an enlarged perspective view of the guide plate of the improved carpenter's square of FIG. 1 showing the guide plate moving between positions; and

[0037] Figures 15A to 15Care perspective and front views of an embodiment of an improved carpenter's square having a jig block for designing a cutting pattern on a workpiece. DETAILED DESCRIPTION

[0038] Reference is now made to the accompanying drawings, in which the same reference numerals are used throughout the different figures to designate the same elements. In short, the embodiments presented herein are preferred exemplary embodiments and are not intended to limit the scope, applicability or configuration of all possible embodiments, but rather to provide an illustrative description of all possible embodiments within the scope and spirit of this specification. The description of these preferred embodiments is generally performed using verbs such as "is" and "are" rather than "may", "may", "include", "include" and the like, because the description is performed with reference to the presented drawings. A person of ordinary skill in the art will understand that changes may be made in the structure, arrangement, number and function of elements and features without departing from the scope and spirit of this specification. In addition, the description may omit certain information that is readily known to a person of ordinary skill in the art to prevent the description from being filled with unnecessary details for inspiration. In fact, the wording used herein is intended to be readable and informative, rather than to describe and limit this specification; therefore, the scope and spirit of this specification should not be limited by the following description and its language selection.

[0039] Figures 1A to 1C A carpenter's square 10 is described. The square includes a body 11 having three edges. Square 10 has: 1) a bevel edge 12 opposite a right angle 15; 2) a first short edge 13 extending between right angle 15 and a first angle 16 formed by and between first short edge 13 and bevel edge 12; and 3) a second short edge 14 extending between right angle 15 and a second angle 17 formed by and between second short edge 14 and bevel edge 12. These three edges cooperate to define a perimeter edge 18 of body 11 of square 10 itself.

[0040] The guide plate 19 is pivotally connected to the first edge 13. The guide plate 19 is a generally rectangular piece of material coextensive with the first edge 13. The guide plate 19 is preferably pivotally connected between three indexed positions. In the first position of the guide plate 19, Figure 1C As shown in solid lines in FIG. 1 , the guide plate 19 is orthogonal to the body 11 in a first direction (into the paper, or away from the reader). In the second position of the guide plate 19, Figure 1C As shown in dashed lines in FIG. 1 , the guide plate 19 is orthogonal to the main body 11 in a second direction opposite to the first direction (away from the paper, or toward the reader). In the third position, the guide plate 19 is coplanar with the main body 11, as shown in FIG. Figure 1A and 1B The two are shown with solid lines.

[0041] When the guide plate 19 is in the first or second position, the carpenter can lay the guide plate 19 flat on the surface and place it against the straight edge and mark the surface. The arrangement of the guide plate 19 orthogonal to the body 11 of the square 10 facilitates quick alignment of the square 10. However, if the carpenter wishes to place the body 11 of the square 10 completely on the workpiece and at least partially inside the straight edge, he only needs to move the guide plate 19 to the third position so that the guide plate 19 is aligned coplanarly with the body 11 and the entire square 10 can be laid flat on the workpiece.

[0042] The body 11 of the square 10 is triangular in shape overall because the perimeter edge 18 has three major sides or lengths overall. The first and second edges 13 and 14 meet at a right angle 15, and the second edge 14 and the hypotenuse edge 12 meet at an acute second corner 17. The first edge 13 and the hypotenuse edge 12 meet at a first corner 16, which is an acute angle but is blunted or truncated by a fourth short edge. Thus, the perimeter edge 18 technically has four sides or four edges, but the very short side at the first corner 16 is so small that the three major sides of the edges 12, 13 and 14 dominate the appearance of the square 10, making the body 11 triangular in shape overall. In this way, the square 10 somewhat specifically has a triangular body 11 defined by the perimeter edge 18 with four sides.

[0043] The body 11 is preferably constructed of a material or a combination of materials having strong, sturdy, durable and rigid material properties. Preferably, the body 11 is made of metal, hardwood, plastic or a similar material that provides these properties.

[0044] The body 11 has a first face 20 and an opposite second face 21. The faces 20 and 21 are flat and parallel to each other, separated by a width W of the body 11, such as Figure 1B . The faces 20 and 21 are marked with various indications and measurements. In addition, slots and slits are formed completely through the body 11 from one face 20 to the other face 21. For example, in Figures 1A to 1C In the embodiment shown in , the middle slit 22 extends diagonally through the body 11. The middle slit 22 is linear or straight. The middle slit 22 has a first end just inside the right angle 15, extends generally at a forty-five degree angle relative to both the first and second edges 13 and 14, and terminates at an opposite second end just inside the bevel edge 12. In other embodiments, the middle slit 22 has other shapes, orientations, and arrangements, and Figures 1A to 1C The embodiment shown in is not limiting. The middle slot 22 can be useful for marking a workpiece beneath the square 10, and is particularly useful in conjunction with a jig block for designing a cutting pattern, as described below.

[0045] Two slots, each wider than the middle slot 22, are formed on the inner sides of the first and second edges 13 and 14. Figure 1A, the first slot 23 is parallel to and inboard of the first edge 13. The first slot 23 has opposing major sides 24 and opposing diagonal minor ends 25. The major sides 24 are both parallel to the first edge 13, and the major sides 24 proximal to the first edge 13 are larger than the major sides 24 distal to the first edge 13. The minor ends 25 are diagonal and point inward at approximately forty-five degrees, such that the minor ends 25 proximal to the second edge 14 are inclined away from the second edge 14 and the minor ends 25 distal to the second edge 14 are inclined toward the second edge 14. Thus, the first slot 23 has the appearance of an isosceles trapezoid. The first slot 23 is open so that a pencil can pass through the first slot 23 to mark a workpiece below the first slot 23. Along the major sides 24 proximal to the first edge 13 of the square 10, the first face 20 is marked with measurement indicators 26. In this embodiment, the measurement indicators 26 are one and a half inch marks measured from the second edge 14. The first of the measurement indicators is a two-inch mark because the first slot 23 is offset from the second edge 14. In other embodiments, the first slot 23, if present, has other shapes, orientations, and arrangements.

[0046] The second slot 30 is parallel to and inside the second edge 14. The second slot 30 has opposing major sides 31 and opposing diagonal minor ends 32. The major sides 31 are both parallel to the second edge 14, and the major sides 31 at the proximal end of the second edge 14 are larger than the major sides 31 at the distal end of the second edge 14. The minor ends 32 are diagonal and point inward at approximately forty-five degrees, so that the minor ends 32 at the proximal end of the first edge 13 are inclined away from the first edge 13 and the minor ends 32 at the distal end of the first edge 13 are inclined toward the first edge 13. Therefore, the second slot 30 has the appearance of an isosceles trapezoid. Like the first slot 23, the second slot 30 is open so that a pencil can pass through it to mark the workpiece below. In other embodiments, the second slot 30 (if present) has other shapes, orientations, and arrangements.

[0047] Another slot, a bevel slot 33, is formed inside the bevel edge 12. The bevel slot 33 is parallel to and inside the bevel edge 12. The bevel slot 33 has opposing major sides 34 and opposing diagonal minor ends 35. The major sides 34 are both parallel to the bevel edge 12, and the major side 34 at the proximal end of the bevel edge 12 is larger than the major side 34 at the distal end of the bevel edge 12. The minor ends 35 are diagonal and point inward at approximately forty-five degrees, so that the minor end 35 proximal to the first edge 13 is parallel to the first edge 13 and the minor end 35 proximal to the second edge 14 is parallel to the second edge 14. Thus, the bevel slot 33 has the appearance of an isosceles trapezoid. The bevel slot 33 is also open so that a pencil can be passed through it to mark the workpiece below. Along both major sides 34, the first face 20 is marked with measurement indicators 36. In other embodiments, the bevel slot 33, if present, has other shapes, orientations, and arrangements.

[0048] The guide plate 19 is hinged to the body 11 to move between three indexed positions. Although in other embodiments, the guide plate 19 is pivoted between an alternative number of positions, for ease and clarity of understanding, the embodiment shown herein is pivoted between three positions. After reading this description, a person of ordinary skill in the art will readily understand how the guide plate 19 moves among an alternative number of positions in such other embodiments.

[0049] The guide plate 19 has a body 40 that is generally rectangular prism-shaped and extends between two opposite ends 41 and 42. The ends 41 and 42 are flat and parallel to each other and are both parallel to the second edge 14. The body 40 of the guide plate 19 includes a guide plate edge 43 extending between the two ends 41 and 42. The guide plate edge 43 is straight and is not interrupted by notches, protrusions, indentations, or other features that would prevent the guide plate edge 43 from defining a straight line. The body 40 includes an inner edge 44 that points to the first edge 13 of the body 11 of the square 10 opposite the guide plate edge 43. Like the first edge 13, the inner edge 44 is interrupted by a hinge assembly that couples the guide plate 19 to the body 11 of the square 10. Both the first edge 13 and the inner edge 44 are slightly rounded with fillets or chamfers so that the guide plate 19 is smoothly pivoted relative to the body 11 without interruption or jamming.

[0050] The body 40 of the guide plate 19 has a first face 45 and an opposed second face 46. The faces 45 and 46 are flat and parallel to each other, spaced apart by the same width W, which defines the width of the body 11 of the square 10. When the guide plate 19 is arranged in its third position, the first face 45 of the guide plate 19 is aligned with and coplanar with the first face 20 of the body 11, and the second face 46 is aligned with and coplanar with the second face 20 of the body 11. Both the first and second faces 45 and 46 are marked with measurement indicators 47 along the guide plate edge 43. The measurement indicators 47 on the first and second faces 45 and 46 are identical, starting at the first end 41 and increasing in number toward the opposed end 42. The guide plate edge 43 also carries a measurement indicator 48 that is aligned with the measurement indicator 47. However, while the measurement indicator 47 preferably includes graduations or hash marks as well as numbers, due to the limited space available on the guide plate edge 43, the measurement indicator 48 preferably includes only hash marks. A carpenter can easily see the numbers on the adjacent first or second face 45 or 46 to identify the measurement.

[0051] The guide plate 19 is preferably mounted to the body 11 of the square 10 at two hinge assemblies 50 (including structural features and elements on both the guide plate 19 and the body 11). Figures 2A to 2D, showing a hinge assembly 50 proximal to the second edge 14. The two hinge assemblies 50 are identical in structure and differ only in position, and thus, the reader will understand that the description of one hinge assembly 50 is equally applicable to the description of the other hinge assembly 50. In other embodiments, there may be fewer or more hinge assemblies 50. Figures 2A to 2D Explanation of the angle square 10 and Figures 1A to 1C The side opposite to the side shown in Figures 2A to 2D The second side 21 is shown instead of the first side 20 .

[0052] The first edge 13 has a rounded chamfer or fillet 51 at both the first and second faces 20 and 21. The fillet 51 allows the guide plate 19 to be pivoted when moving among different positions. Inside the second edge 14, a notch 52 interrupts the first edge 13. The notch 52 is concealed and extends into the body 11 of the square 10, terminating at an inner wall extending between two sides 53 and 54 of the notch 52. The notch 52 defines a receiving space complementary to a tab 55 on the guide plate 19, which fits into the notch 52.

[0053] The tab 55 is an integral, one-piece, one-piece protrusion of the body 40 at the inner edge 44 of the guide plate 19. The tab 55 has two opposing ends 56 and 57 orthogonal to the inner edge 44 and an inner edge 58 extending between the ends 56 and 57. Like the inner edge 44 of the guide plate 19 itself, the inner edge 58 is rounded. The distance between the ends 56 and 57 is approximately half to two-thirds of the distance between the sides 53 and 54 of the notch 52, and therefore the tab 55 fits easily within the notch 52.

[0054] The tab 55 is mounted on a pin or shaft 60. Preferably, a hole 61 extends completely through the tab 55 between the ends 56 and 57 of the tab 55. The shaft 60 is mounted between the sides 53 and 54 of the notch 52 and is snugly received in the hole 61 so that the tab 55 and the guide plate 19 connected thereto are mounted for pivotal movement about an axis defined by the shaft 60. A compression spring 62 is mounted over the shaft 60 and is compressed between the end 56 of the tab 55 and the side 53 of the notch 52. The compression spring 62 biases the tab 55 toward the other side 54 of the notch 52, which is defined as the neutral position. In the neutral position, the tab 55 prevents the guide plate 19 from moving among its three positions. In the neutral position, the end 57 of the tab 55 is in contact with the side 54 of the notch 52, as shown in FIG. Figure 2A In the neutral position, the guide plate 19 maintains coextensive alignment with the main body 11 of the square, as shown in FIG. Figure 1A end 41 is aligned with the second edge 14, and end 42 is aligned with the first corner 16.

[0055] When the neutral position makes it impossible for the guide plate 19 to move among its three positions, the tab 55 can be moved out of this neutral position and into the forward position, such as Figure 2B and 2C In the forward position, the tab 55 enables the guide plate 19 to move among its three positions. To move the guide plate 19 and the tab 55 out of the neutral position and into the forward position, the carpenter simply grasps the body of the guide plate 19 and moves along the first edge 13 of the square 10, along Figure 2B The arrow line S in FIG. slides the guide plate 19 upward. Sliding the guide plate 19 in this way compresses the spring 62, and therefore the carpenter must use force to move the guide plate 19 to the forward posture.

[0056] The engagement assembly prevents the tab 55 from accidentally moving out of the third position. When the tab 55 is in the neutral position, the guide plate 19 is blocked or unable to move into the first or second position. Only when the tab 55 is in the advanced position can it move so that the guide plate 19 can move to the first or second position. The groove 64 is slightly downturned into the second face 21 of the body 11. The groove 64 is formed into the body 11, communicates with the notch 52, and extends from the notch 52 across the second face 21 of the body 11 toward the second edge 14. The same groove 63 ( Figure 1A and 1B ) extends into the first face 20 on the other side of the body 11, and another groove 65 ( Figure 1B ) is formed into the first edge 13 itself. Each of the grooves 63 to 65 is a substantially semi-cylindrical cavity.

[0057] A tongue 66 complementary to the groove 64 is carried on the guide plate 19. The tongue 66 is a semi-cylindrical protrusion formed on the inner edge 44 of the guide plate 19. The tongue 66 has a longitudinal axis parallel to the first edge 13 of the guide plate 19. The tongue 66 has a proximal end that is integrally and monolithically formed with the end 57 of the tab 55 and extends along the inner edge 44 from the end 57 to the distal end of the tongue 66, presenting a semi-cylindrical convex surface outwardly between the proximal and distal ends. The tongue 66 is sized and shaped to be closely received within each of the grooves 63 to 65 formed in the body 11 of the square 10.

[0058] As the tab 55 moves among the first, second, and third positions of the guide plate 19, the tongue 66 moves in and out of the grooves 63 to 65 to temporarily lock the guide plate 19 in the first, second, and third positions. When the guide plate 19 is in the first position, the groove 64 receives the tongue 66, and the interaction of the tongue 66 with the groove 64 prevents the guide plate 19 from pivoting relative to the body 11. When the guide plate 19 is in the second position, the groove 63 receives the tongue 66, and the interaction of the tongue 66 with the groove 63 prevents the guide plate 19 from pivoting relative to the body 11. And when the guide plate 19 is in the third position, the groove 65 receives the tongue 66, and the interaction of the tongue 66 with the groove 65 prevents the guide plate 19 from pivoting relative to the body 11.

[0059] When the guide plate 19 is in each of the first, second and third positions, if the carpenter attempts to pivot the guide plate 19 to another position, the tongue 66 contacts the side of the corresponding groove 63 to 65 and is prevented from pivoting. Therefore, each time the tongue 66 is received in one of the grooves 63 to 65, the guide plate 19 cannot move unless the tab 55 is first moved out of the neutral posture. Thus, in this embodiment, the first, second and third positions of the guide plate 19 are defined, discrete and indexed positions. In this embodiment, the guide plate 19 can only be placed and temporarily locked into one of these three indexed positions. Other embodiments have a fewer or greater number of positions (indexed or otherwise). The guide plate 19 is temporarily locked because it is effectively prevented from being accidentally or accidentally moved out of the position, but the carpenter can easily and purposefully move the guide plate 19 out of the position by overcoming the spring force of the compression spring 62 and sliding the guide plate 19 upward into the forward posture of the tab 55. Thus, the tongue 66 and the grooves 63 to 65 define an engagement assembly or spring pawl assembly for locking and releasing the guide plate 19 .

[0060] When the carpenter wishes to move the guide plate 19 into another position (e.g., from the third position to the first position, e.g., Figures 2A to 2D ), he first slides the tab 55 out of the neutral position and into the forward position, such as from Figure 2A to 2B This causes the tongue 66 to slide longitudinally out of the groove 65. The spring 62 exerts a bias on the tab 55 to return it to the neutral position, and therefore the carpenter must hold the guide plate 19 to prevent it from returning to the neutral position. While still grasping the guide plate 19 in the advanced position, the carpenter moves the guide plate 19 along the Figure 2C The arc-shaped arrow line P moves the guide plate 19 and pivots the guide plate 19 to that side. Figure 2C When in the position shown in FIG. 1 , the tongue 66 is aligned with the groove 64 but is longitudinally offset from the groove 64. The carpenter can then release the guide plate 19 and allow the spring 62 to move along the groove 64 as shown in FIG. Figure 2DThe arrow line S' shown in FIG. 1 biases the guide plate 19 back to the neutral position. When the guide plate 19 moves back to the neutral position, the tongue 66 is received and engaged by the groove 64 on the second face 21. The guide plate 19 is now temporarily locked into the first position.

[0061] The guide plate 19 is preferably made of the same material as the body 11 of the square 10. Figure 1A In some embodiments, the guide plate 19 includes a magnetic element, an example of which is shown in phantom with reference numeral 67 . Figure 1A The magnetic elements 67 shown in FIG. 1 are circular, disc-shaped magnets and are enclosed within the body 40 of the guide plate 19. In other embodiments, the magnetic elements 67 may be offset within the body 40 or flush with one of the first or second faces 45 and 46. The embodiment shown herein has three magnetic elements 67 spaced along the length of the guide plate 19. The magnetic elements 67 are useful for aligning and holding a square during metalworking. Some embodiments of the guide plate 19 have fewer magnetic elements 67 than shown herein, some have more magnetic elements 67, and some have no magnetic elements 67 at all.

[0062] Reference again Figures 2A to 2D , the square 10 has a dual measurement system. When the guide plate 19 is in any of the first, second or third positions, measurements can be taken along the second edge 14 by the guide plate 19. The second edge 14 has two sets of measurement indicators or two sets of measurements. The first set 71 of measurement indicators are marked along the second edge 14. This first set 71 Figure 1A 10 is identifiable in the figure because the measurement numbers (1, 2, 3, etc.) are oriented with their tops towards the lower left in the figure. The first group 71 has a zero position 73 from which the remaining indicators in the first group 71 are measured and to which the first group 71 corresponds. This zero position 73 corresponds to the position of the first face 45 or the second face 46 of the guide plate 19 when the guide plate 19 is pivoted to the second position or the first position, respectively. When the guide plate 19 is so pivoted, the face of the guide plate 19 that points toward the body 11 of the square 10 defines a plane from which measurements are taken, because that face defines an internal angle that is placed against the edge of the workpiece. Thus, the first group 71 of measurement indicators can be useful for measurement when the guide plate 19 is in either the first or the second position.

[0063] However, when the guide plate 19 is in the third position, the zero position 73 is no longer relevant. The second set 72 of measurement indicators are marked along the second edge 14 and are useful in this case. The second set 72 has a zero position 74 from which the remaining indicators in the second set 72 are measured and to which the second set 72 corresponds. This zero position 74 corresponds to the guide edge 43 of the guide plate 19 when the guide plate 19 is pivoted to its third position. When the guide plate 19 is so arranged, the square 10 can lie flat against a flat workpiece with the guide edge 43 defining a plane from which measurements are taken, as the guide edge 43 will be placed along a line, edge or similar marking.

[0064] The first and second sets 71 and 72 of measurement indicators share the same hash mark 75. Thus, depending on the arrangement of the guide plate 19, the hash mark 75 can be read with either the first or second set 71 and 72 of measurement indicators. However, the numbering indicia of the first and second sets 71 and 72 are different. The second zero position 74 is offset from the first zero position 73, and therefore the numbering indicia of the second set 72 of measurement indicators is offset from the first set 72 of measurement indicators.

[0065] The body 11 of the square 10 carries at least three other useful structures. Figure 1A , near the middle of the body 11, the body 11 carries the laser 80 and the jig block 81, and near the second corner 17, the body carries a bubble level 82. The bubble level 82 is preferably a feature of the carpenter's square 10, but it does not have to be a feature thereof. In addition, other embodiments of the bubble level can be used, as described later. In addition, this bubble level 82 and those embodiments described later can also be incorporated into other types of levels, such as torpedo levels, carpenter or box levels, column levels, and other levels.

[0066] refer to Figure 1A And also refer to Figure 2A , a laser 80 is preferably carried in the body 11 of the square and directs a laser beam out of the square 10 parallel to the first edge 13. The laser 80 comprises a laser emitter shown in phantom in the body 11. The laser emitter has an emitting end 83 directed toward the second edge 14. The laser 80 emitter is carried in a bracket in the body 11 of the square 10, and a hole extends completely from that bracket to the second edge 14. To maintain the clarity of the drawings, the hole is not shown in the drawings, but the open terminal end of the hole is shown as an opening 84 on the second edge 14, as shown in FIG. Figure 2A84. The laser 80 emits a laser beam (identified by reference numeral L in dashed lines) through the hole and out of the opening 84. The laser 80 is oriented, and the hole is aligned in that orientation, so that the laser beam L is parallel to the first edge 13 and therefore also parallel to the guide plate 19. This allows a carpenter to set or hang the square 10 on its guide plate 19 or one of the first or second faces 45 and 46 atop a workpiece and direct the laser beam L parallel to that workpiece. In addition, the laser 80 is preferably aligned with one of the unit markings of the first and second sets 71 and 72 of measurement indicators to allow for easier offset measurement calculations when aiming with the laser 80.

[0067] The main reference Figure 1C , showing one embodiment of a bubble level 82. The bubble level 82 shown is a single hollow tube, preferably having three sections: a horizontal section 90, a diagonal section 91, and a vertical section 92. Sections 90, 91, and 92 are communicatively joined to one another to define the tube as a single, one-piece tubular element. However, each section is oriented differently relative to the other sections to allow a carpenter to find the level in different ways.

[0068] The tube of the bubble level 82 has a closed sidewall 93. The sidewall 93 is preferably tubular and transparent. In some embodiments, the sidewall 93 is cylindrical, while in other embodiments it is a rectangular prism, and in other embodiments it has other shapes. The sidewall 93 is carried in a bracket 94, which is open to both the first face 20 and the second face 21 so that the bubble level 82 can be observed from both sides of the square 10. The tube is filled with a fluid (such as water, ethanol or ethylene glycol), and that fluid is preferably colored to provide a contrast with the bubbles 95 in the fluid. The sidewall 93 is closed at both ends so that the fluid does not leak.

[0069] Horizontal section 90 is aligned parallel to first edge 13 and orthogonal to second edge 14. It extends from the closed end of the tube to diagonal section 91. The tube has a discrete and angled transition from horizontal section 90 to diagonal section 91. Diagonal section 91 is orthogonal to hypotenuse edge 12 and is at a forty-five degree angle relative to both first and second edges 13 and 14. Diagonal section 91 extends from horizontal section 90 to vertical section 92. The tube has a discrete and angled transition from diagonal section 91 to vertical section 92. Vertical section 92 is parallel to second edge 14 and orthogonal to first edge 13. Because diagonal section 91 is in fluid communication with both horizontal and vertical sections 90 and 92, air bubbles 95 can easily move among each section 90, 91 and 92 as the carpenter handles square 10.

[0070] Each section 90, 91, and 92 has a pair of horizontal lines 96. The horizontal lines 96 are marked in the center of each section, spaced a distance just greater than the diameter of the bubble 95. When the first edge 13 of the square 10 is placed against an object and the bubble 95 is between the lines 96 without touching the lines 96, the bubble level 82 indicates that the surface of the object has a particular measurement. If the bubble 95 touches one of the lines, then the surface of the object deviates from that particular measurement, for example by 2% or another value. If the bubble 95 is further outside the lines, then the surface of the object deviates further from that particular measurement.

[0071] In use, the carpenter places the first edge 13 or the guide edge 43 against the surface of the object. Depending on the orientation of the object, one of the sections 90, 91 and 92 will likely be of interest. For example, if the surface is nearly horizontal (e.g., on top of a beam), the carpenter will refer to the horizontal section 90 of the bubble level 82. The bubble 95 will float to the horizontal section 90 and rest somewhere in or near the line 96 in the horizontal section 90. This will tell the carpenter how close the beam is to being horizontal. On the other hand, if the carpenter wants to check whether the pillar supporting the beam is vertical, he will place the first edge 13 (or the guide edge 43) against the side of the pillar while the second edge 14 is facing upward, and then refer to the vertical section 92 of the bubble level 82. Rearranging the square 10 in this way causes the bubble 95 to move into the vertical section 92 and rest somewhere in or near the line 96 in the vertical section 92. The carpenter now knows how close the pillar is to being vertical in that direction. Finally, if the carpenter wants to check a bracket that extends more or less diagonally from the post to the beam, he places the first edge 13 (or guide edge 43) against the upper or lower side of the bracket and references the diagonal section 91 of the bubble level 82. Rearranging the square 10 in this way causes the bubble 95 to move into the diagonal section 91 and rest somewhere in or near the line 96 in the diagonal section 91. The carpenter now knows how close to forty-five degrees the diagonal angle between the post and the beam actually is. This single bubble level 82 allows three different measurements.

[0072] Replacement bubble level in Figures 3A to 3C . The bubble level 86 is similar to the bubble level 82 and shares many of the same structural elements and features. Thus, the description of the bubble level 86 employs the same reference numerals as used just above to describe the bubble level 82, but the reference numerals are marked with a prime ("'") to distinguish them from those of the bubble level 82. The bubble level 86 is a single hollow tube preferably having two sections: a horizontal section 90' and a vertical section 92', which are communicatively joined to one another to define the tube as a single, one-piece tube. The two sections are oriented differently relative to one another to allow the carpenter to find the level in different ways.

[0073] The tube of the bubble level 86 has a closed sidewall 93'. The sidewall 93' is preferably transparent. In some embodiments, the sidewall 93' is cylindrical, while in other embodiments it is a rectangular prism, and in other embodiments it has other shapes. The sidewall 93' is carried in a bracket 94', which is open to both the first face 20 and the second face 21 so that the bubble level 86 can be observed from both sides of the square 10. The tube is filled with a fluid (such as water, ethanol or ethylene glycol), and that fluid is preferably colored to provide a contrast with the bubbles 95' in the fluid. The sidewall 93' is closed at both ends so that the fluid will not leak.

[0074] The horizontal section 90' is aligned parallel to the first edge 13 and orthogonal to the second edge 14. It extends from the closed end of the tube to a right angle formed with the vertical section 92'. The tube has a discrete and angled transition from the horizontal section 90 to that vertical section 92'. The vertical section 92' is parallel to the second edge 14 and orthogonal to the first edge 13. The air bubble 95' can easily move between the sections 90' and 92' when the carpenter handles the square 10.

[0075] Still refer to Figures 3A to 3C , this specification describes the use and operation of a jig block 81. The jig block 81 converts the square 10 into a jig that quickly and easily designs a line pattern for marking cuts along the edge of a workpiece, such as for patterned cuts of stair stringers from 2×12 lumber pieces. The jig block 81 is a thin piece of material, preferably made of the same material as the body 11 of the square 10, having a long edge 100 and a through hole 101. The jig block 81 is held in place in the body 11 until needed, when the carpenter removes the jig block 81, secures it to the middle slit 22, and uses the entire square to design a pattern of cut lines.

[0076] The jig block 81 is carried in a bracket 102 of the body 11 of the square 10. The bracket 102 is a blank space sized and shaped to snugly receive and hold the jig block 81. In embodiments, the bracket 102 has overlapping inner edges so that the jig block 81 can be removed only through one side of the bracket 102 and one side of the square 10. In other words, in those embodiments, the size of the bracket on one side of the square 10 is slightly smaller than the size of the bracket on the other side of the square 10 (and slightly smaller than the jig block 81 itself), so that the jig block 81 cannot be removed through the smaller side, but can only be removed through the larger side.

[0077] The jig block 81 has a long edge 100. The long edge 100 is straight and is not interrupted by notches, protrusions, indentations or other discontinuities. The embodiment of the jig block 81 shown in these figures has four other edges arranged to form a shape generally similar to a baseball home plate. Other shapes are also suitable, as long as the jig block 81 has a long edge 100. The jig block 81 itself is thin and no thicker than the thickness of the body 11 of the square 10, so that the jig block 81 can be stored in the square and will not interfere with the use of the square 10 when the jig block 81 is so stored.

[0078] In use, the jig block 81 is removed from the bracket 102. In some embodiments, the jig block 81 is magnetic and is magnetically fixed in the bracket 102. In other embodiments, a small turning screw disposed at the edge of the bracket 102 selectively locks and releases the jig block 81. In other embodiments, the jig block 81 is simply tightly fitted and held in the bracket 102. Regardless of how the jig block 81 is held, it can be removed from the bracket 102. Pick up the jig block 81 by hand and place it against one of the first and second faces 20 and 21. Figure 3B 10 , by way of example only, the jig block 81 is placed against the first face 20. The jig block 81 is oriented so that its long edge 100 is generally pointing at the right angle 15 and its through hole 101 is aligned with the middle slit 22. The carpenter takes the fixing screw 103 and passes it through the through hole 101 and the middle slit 22. In some embodiments, the fixing screw 103 can be screwed directly into the middle slit 22, but more preferably, a nut is placed over the free end of the fixing screw 103 and tightened thereon, thereby binding the jig block 81 against the body 11 of the square 10. In an embodiment, the fixing screw 103 is stored in or on the square 10. For example, Figure 3A Shown in phantom is a set screw 103 secured in a small threaded hole 104 extending into the bevel edge 12, which is not commonly used as a marking edge. In other embodiments, the set screw 103 may be stored in a hole on the jig block 81 itself.

[0079] Once the jig block 81 is attached to the face 20 of the square 10, the square 10 is picked up by hand, turned upside down and placed over a workpiece 108 (e.g., a piece of wood), such as Figure 3C The workpiece 108 has an outer edge 109 along which the cut is made. In order to place the entire face 20 of the square on top of the workpiece 108, the carpenter must move the guide plate 19 to its third position flat and coplanar relative to the body 11 of the square 10.

[0080] exist Figure 3CIn the figure, the jig block 81 is below the square 10 and is therefore shown substantially in phantom. The carpenter manipulates the square 10 so that the long edge 100 is placed directly and continuously in contact with the outer edge 109 of the workpiece 108. This causes the square 15 and most of the body 11 of the square 10 to be placed above the workpiece 108.

[0081] Next, the carpenter adjusts the jig block 81 to ensure that the square 10 marks the desired pattern. The carpenter will cut a predetermined pattern. For example, if he is cutting a stringer, he will need to know the step height and step width, such as 7.5 inches and 11 inches. With the long edge 100 of the jig block 81 against the workpiece 108, the carpenter slightly loosens the set screw 103 so that the square 10 can move relative to the jig block 81. The carpenter moves the square 10 to achieve the desired step height and step width. This may require sliding the square 10 so that the jig block 81 moves up or down along the middle slit 22. It may also be necessary to rotate the body 11 of the square 10 while the jig block 81 remains against the outer edge 109.

[0082] When the carpenter has aligned the square 10 on the work piece so that the outer edge 109 intersects the desired step height and step width measurements, he tightens the set screw 103. It should be noted that the carpenter uses the measurement indicators 47 along the guide plate 19 and the second set 72 of measurement indicators along the second edge because the guide plate 19 is in its third position and the carpenter must use the offset second set 72.

[0083] With the square 10 properly adjusted, the carpenter can now quickly design the cutting lines. He draws the first set of lines A1 and A2, such as Figure 3C The top of the workpiece 108 is shown. Lines A1 and A2 define two cuts made at right angles using the desired step height and step width measurements. The carpenter then translates the square down along the workpiece 108 to a second position along the arrow line T. Figure 3C The second position shown in FIG. 1 as being occupied by the square begins at the end of line A2, where line A2 intersects outer edge 109. The carpenter then marks lines B1 and B2 along guide edge 43 and second edge 14, respectively. He then continues to translate square 10 and mark successive lines, thereby quickly designing the desired cutting pattern.

[0084] Figure 4Another embodiment of a carpenter's square 110 is described. The carpenter's square 110 is similar in many respects to the square 10 and shares many of the same structural elements and features as the square 10. As such, the square 110 uses the same reference numerals to describe the same features, but the reference numerals are marked with a prime ("'") to distinguish the structural elements and features of the square 110 from those of the square 10. For example, while the square 10 has a guide plate 19, the square 110 has a guide plate 19'. The guide plates 19 and 19' are identical in every respect, but because the guide plate 19' is part of the square 110, its reference numerals are marked with a prime. Because structures such as these structures have been described with respect to the square 10, the structures are generally not further described in this specification with respect to the square 110. Other structures that have not yet been introduced or that are different have unique reference numerals.

[0085] Square 110 includes a body 111 that is generally triangular in shape with a long leg extending continuously from one side. Square 110 has: 1) a hypotenuse edge 112 opposite to right angle 15'; 2) a first short edge 13'; and 3) a second long edge 114. Guide plate 19' is pivoted to first edge 13' and, like guide plate 19, is pivoted in three locations. Figure 4 , the first and second positions of the guide plate 19' are shown in dashed lines, orthogonal to the body 11, and the third position is illustrated in solid lines. The guide plate 19' is pivotally connected to the body 111 by an engaging assembly of a tab 55', a shaft 60', a spring 62', a tongue 66' and a groove 63' to 65'. The tongue 66' and the groove 63' to 65' are not labeled in the drawings, but the reader can understand their position, structure and function from the above description of the same tongue 66 and groove 63 to 65.

[0086] The body 111 of the square 110 and the guide plate 19' are preferably constructed of a material or combination of materials having strong, sturdy, durable and rigid material properties. Preferably, the body 11 is made of metal, hardwood, plastic or a similar material that provides these properties. The body 11 has a first face 120 and an opposing second face 121, the second face 121 being marked and opposite the first face 120, but having a Figure 4 The surfaces 120 and 121 are flat and parallel to each other, separated by the width X of the body 111, as shown in FIG. Figure 4 Surfaces 120 and 121 are labeled with various indications and measurements.

[0087] Additionally, slots and slits are formed completely through the body 111 from the first face 120 to the other second face 121. The body 111 includes a middle slit 22', a first slot 23', a second slot 30', and a bevel slot 33'. These slots are useful for marking through the square 110 and attaching a jig block 81' to the square 110 when the carpenter desires to design a cutting pattern.

[0088] Unlike square 10, square 110 has an extension or leg 124 protruding from one corner. Leg 124 is a generally rectangular piece of material integrally and monolithically formed to body 111 as part of body 111. Second edge 114 is longer and extends continuously along a main portion of body 111 and leg 124. Leg 124 extends from the main portion of body 111 to a blunt terminal edge 125. Terminal edge 125 is linear, straight, and parallel to first edge 13'. In other embodiments, terminal edge 125 has other shapes.

[0089] Leg 124 defines a continuous extension of second edge 114, as it generally shares and extends second edge 114. That second edge 114 has two sets of measurement indicators. A first set 131 of measurement indicators are marked along second edge 114. This first set 131 is Figure 4 110 are identifiable in the figure because the measurement numbers (1, 2, 3, etc.) are oriented with their tops towards the left in the figure. The first group 131 has a zero position 133 from which the remaining indicators in the first group 131 are measured and to which the first group 131 corresponds. This zero position 133 corresponds to the position of the first face 45' or the second face 46' of the guide plate 19' when the guide plate 19' is pivoted to the second position or the first position, respectively. When the guide plate 19' is so pivoted, the face of the guide plate 19' that points toward the body 111 of the square 110 defines a plane from which measurements are taken because that face is placed against the edge of the workpiece. Thus, the first group 131 of measurement indicators are useful for measurement when the guide plate 19' is in either the first or the second position.

[0090] However, when the guide plate 19' is in the third position, the zero position 133 is no longer relevant. The second set 132 of measurement indicators are marked along the second edge 114 and are useful in this case. The second set 132 has a zero position 134 from which the remaining indicators in the second set 132 are measured and to which the second set 132 corresponds. This zero position 134 corresponds to the guide plate edge 43' of the guide plate 19' when the guide plate 19' is pivoted to its third position. When the guide plate 19' is arranged, the square 110 can lie flat against a flat workpiece and the guide plate edge 43' defines a plane from which measurements are taken, as the guide plate edge 43' will be placed along a line, edge or similar marking.

[0091] The first and second sets 131 and 132 of measurement indicators share the same hash mark 135. Thus, depending on the arrangement of the guide plate 19', the hash mark 135 can be read with either the first or second set 131 and 132 of measurement indicators. However, the numbering indicia of the first and second sets 131 and 132 are different. The second zero position 134 is offset from the first zero position 133, and therefore the numbering indicia of the second set 132 of measurement indicators is offset from the first set 132 of measurement indicators.

[0092] Unlike the second edge 14 of the square 10 (which preferably extends approximately twelve inches), the legs 124 extend the second edge 114 (preferably) sixteen inches. In other embodiments, the lengths may be longer or shorter. The reader will understand that none of the lengths described herein are critical, and that the disclosed scope of each embodiment encompasses different lengths (both short and long). For example, the square 110 may be only a few inches long or may be two feet or longer.

[0093] Like square 10, square 110 preferably carries laser 80', jig block 81' and bubble level 140. However, bubble level 140 is different from bubble level 82. Bubble level 140 is one embodiment of a bubble level. Bubble level 140 is a hollow tube having a continuous arc shape. The arc preferably extends one hundred and eighty degrees, but it can be shorter or longer in other embodiments. In this embodiment, the arc extends from one end 147 proximal to the bevel edge upward and around the leg 124, and then back down to the opposite end 148 proximal to the second edge 114. Different portions of this arc allow the carpenter to find level in different ways.

[0094] The tube of the bubble level 140 has a closed sidewall 141. The sidewall 141 is preferably transparent. In some embodiments, the sidewall 141 is cylindrical, while in other embodiments it is a rectangular prism, and in other embodiments it has other shapes. The sidewall 141 is carried in a bracket 142, which is open to both the first face 120 and the second face 121 so that the bubble level 140 can be observed from both sides of the square 110. The tube is filled with a fluid (such as water, ethanol or ethylene glycol), and that fluid is preferably colored to provide a contrast with a float 143 in the fluid. The float 143 is preferably a bubble in the fluid, but in other embodiments the float is a small, transparent and rigid sphere or capsule. The tube is closed at both ends 147 and 148 so that the fluid does not leak. The sidewall 141 is curved from one closed end 147 to the other closed end 148.

[0095] Figure 4The embodiment shown in includes three pairs of horizontal lines. The first set 144 of horizontal lines are marked proximal to an end 147 of the bubble level 140, which is located proximal to the bevel edge 112. The first set 144 of horizontal lines are marked in a radial direction through the tube and are spaced apart by a distance just greater than the diameter of the float 143. The second set 145 of horizontal lines are marked midway between the ends of the bubble level 140. The second set 145 of horizontal lines are marked in a radial direction through the tube and are spaced apart by a distance just greater than the diameter of the float 143. The third set 146 of horizontal lines are marked proximal to an end of the bubble level 140, which is located proximal to the second edge 114. The third set 146 of horizontal lines are marked in a radial direction through the tube and are spaced apart by a distance just greater than the diameter of the float 143.

[0096] The bubble level 140 shown in this embodiment of the square 110 is only one embodiment. Other carpenter's squares according to the scope of the present disclosure may include other bubble levels described herein, such as the bubble level 82 or the bubble levels described later. Likewise, although Figure 4 The embodiment shown in FIG. 1 includes a fixture block 81 ', but other embodiments do not include a fixture block 81 ', and although Figure 4 Embodiments include laser 80', but other embodiments do not include laser 80'.The scope of the present disclosure and described embodiments includes all permutations of the various structural elements and features of all embodiments disclosed herein.

[0097] The first, second and third sets 144, 145 and 146 of horizontal lines are useful for measuring different inclinations of the surface of an object. In use, the carpenter places the first edge 13' or the guide edge 43' against the surface of the object. If that surface is close to horizontal (e.g., on the top of a beam), the carpenter will refer to the first set 144 of horizontal lines. The float 143 will float to the top of the bubble level 140 and rest somewhere in or near that set 144 of horizontal lines. This tells the carpenter how close the beam is to horizontal. If the float 143 touches one of the lines, then the surface of the object deviates from that particular measurement, for example, by 2% or another value. If the float 143 is further outside the lines, then the surface of the object deviates further from that particular measurement.

[0098] On the other hand, if the carpenter wants to check whether the leg of the support beam is vertical, he will place the first edge 13' (or the guide edge 43') against the side of the leg with the second edge 114 facing upward, and then refer to the side of the bubble level 140. Rearranging the square 110 in this way causes the float 143 to rest somewhere in or near the third set of lines 146. The carpenter now knows how close to vertical the leg is in that direction.

[0099] Finally, if the carpenter wants to check a bracket that extends more or less diagonally from the post to the beam, he would place the first edge 13' (or the guide edge 43') against the upper or lower surface of the bracket and reference the second set 145 horizontal lines of the bubble level 140. Rearranging the square 110 in this way causes the float 143 to rest somewhere in or near the second set 145 lines. The carpenter now knows how close to forty-five degrees the diagonal between the post and the beam actually is. This single bubble level 140 allows three different measurements.

[0100] Figure 5 and 6 Another embodiment of a carpenter's square 160 is described. The carpenter's square 160 is similar in many respects to the square 10 and shares many of the same structural elements and features as the square 10. Therefore, the square 160 uses the same reference numerals to describe the same features, but the reference numerals are marked with double primes (""") to distinguish the structural elements and features of the square 160 from those of the square 10. For example, while the square 10 has a guide plate 19, the square 160 has a guide plate 19". The guide plates 19 and 19" are identical in every respect, but because the guide plate 19" is part of the square 160, its reference numeral is further designated with a prime. Because structures such as these structures have been described with respect to the square 10, the present specification generally does not further describe such structures with respect to the square 160.

[0101] Square 160 is particularly useful to a metal worker or metal craftsman. Square 160 includes a body 161 that is generally triangular in shape and has three main edges. Square 160 has: 1) a bevel edge 12" opposite a right angle 15"; 2) a first short edge 13"; and 3) a second short edge 14". These three edges cooperate to define a perimeter edge 18" of the body 161 of square 160 itself. Within perimeter edge 18" carried in body 161 is an embodiment of a bubble level 180 that a metal worker can use to determine measurements within a range of angles.

[0102] A substantially rectangular guide plate 19" is pivoted to the first edge 13" and, like the guide plate 19, is pivoted in three positions. Figure 5 , the first and second positions of the guide plate 19" are shown in dashed lines, orthogonal to the body 161, and the third position is illustrated in solid lines. The guide plate 19" is provided by the tab 55", the shaft 60", the spring 62", the tongue 66" and the groove 63" to 65" ( Figure 5 The engaging assembly (not shown) is pivotally connected to the main body 161.

[0103] The body 161 of the square 160 and the guide plate 19" are both preferably constructed of a material or combination of materials having strong, sturdy, durable and rigid material properties. Preferably, the body 161 is made of metal, hardwood, plastic or a similar material that provides these properties. The body 161 has a first face 170 and an opposing second face 171, such as Figure 6 The first and second faces 170 and 171 are flat and parallel to each other, separated by the width of the body 161, as shown in FIG. Figure 6 As shown in . Figure 6 It is along Figure 5 A cross-sectional view taken along line 6-6 in FIG.

[0104] The first and second faces 170 and 171 are marked with a plurality of indications and measurements. In addition, slots and slits are formed completely through the body 161 from the first face 170 to the other second face 171. The body 161 includes a first slot 23" and a beveled slot 33". These slots are useful for marking through the square 160.

[0105] The second edge 14" has two sets of measurement indicators. The first set 71" of measurement indicators are marked along the second edge 14". This first set 71" Figure 5 160 . The first set 71" is identifiable in the drawings because each of the measurement numbers (1, 2, 3, etc.) is oriented with its top toward the left in the drawing. The first set 71" has a zero position 73", from which the remaining indicators in the first set 71" are measured and to which the first set 71" corresponds. This zero position 73" corresponds to the position of the right angle 15" and the first face 45" or the second face 46" (not shown) of the guide plate 19" when the guide plate 19" is pivoted to the second position or the first position, respectively. When the guide plate 19" is so pivoted, the face of the guide plate 19" that points toward the body 161 of the square 160 defines a plane from which measurements are taken because that face is placed against the edge of the workpiece. Thus, the first set 71" of measurement indicators are useful for measurement when the guide plate 19" is in the first or second position.

[0106] However, when the guide plate 19" is in the third position, the zero position 73" is no longer relevant. The second set 72" of measurement indicators are marked along the second edge 14" and are useful in this case. The second set 72" has a zero position 74", the remaining indicators in the second set 72" are measured from said zero position 74" and the second set 72" corresponds to said zero position 74". When the guide plate 19" is pivoted to its third position, this zero position 74" corresponds to the guide edge 43" of the guide plate 19". When the guide plate 19" is so arranged, the square 160 can lie flat against a flat workpiece and the guide edge 43" defines the plane from which measurements are taken, as the guide edge 43" will be placed along a line, edge or similar marking.

[0107] The first and second sets 71″ and 72″ measurement indicators share the same hash mark 75″. Therefore, depending on the arrangement of the guide plate 19″, the hash mark 75″ can be read with the first or second set 71″ and 72″ measurement indicators. However, the numbering indicia of the first and second sets 71″ and 72″ are different. The second zero position 74″ is offset from the first zero position 73″, and therefore the numbering indicia of the second set 72″ measurement indicators is offset from the first set 72″ measurement indicators.

[0108] In this embodiment of square 160, three edges 12", 13", and 14" define body 161 as a triangular shape. However, the scope of the embodiment of square 160 is not limited in this regard. For example, in other embodiments, square 160 includes legs similar to legs 124 of square 110.

[0109] Like square 10, square 160 preferably carries a bubble level, but Figure 5 and 6 The bubble level 180 shown for the square 160 is different from the bubble level 82 of the square 10. The bubble level 180 is one embodiment of a bubble level. Figure 5 and Figure 6 Both, bubble level 180 defines a saucer-shaped container filled with fluid and a single float or bubble used to find the measurement.

[0110] The bubble level 180 has a central hub and a ring surrounding the hub, and a float freely floats between the hub and the ring depending on the orientation of the square 160. The bubble level 180 is set into a bracket 181 in the body 161 of the square 160. The bracket 181 is a generally cylindrical hole formed through the body 161 from the first face 170 to the second face 171, thereby defining an inner wall 182. The bubble level 180 fits tightly into the bracket 181, but in some embodiments, the bubble level 180 is fixed in the bracket 181 not only by a tight fit but also by an adhesive or some other fastener.

[0111] The bubble level 180 is formed by a thin sidewall 183, which is preferably symmetrical about a central plane parallel to the first and second faces 170 and 171. The sidewall 183 has a first wall 184 and a second wall 185 that are preferably symmetrical to each other. The first and second walls 184 and 185 intersect at the inner wall 182 and delimit and define a container having a disc shape. The first and second walls 184 and 185 extend radially inward from the inner wall 182, expanding outward away from each other until an inflection point 186. The inflection point 186 is a generally circular boundary between the ring (outside the inflection point 186) and the hub (inside the inflection point 186). Within the inflection point, the first and second walls 184 and 185 each define a truncated or cut-off sphere having only a circular portion that is less than a hemisphere. The first and second walls 184 and 185 work together to define a generally egg-shaped space at the hub within the inflection point 186. In other embodiments, this hub has other shapes.

[0112] In the inflection point 186, both the first and second walls 184 and 185 rise to a top 189 that is flush with or just inside the first and second faces 170 and 171, respectively. Thus, the bubble level 180 is bounded within the body 161 by the first and second faces 170 and 171. In other embodiments, the bracket 181 and / or the bubble level 180 extend beyond these faces 170 and 171, but in such other embodiments, the bubble level 180 may be scratched and damaged.

[0113] Walls 184 and 185 are preferably transparent so that a metal worker can view the bubble level 180 from either side of the square 160 and observe the interior 187 of the bubble level 180. The interior 187 is substantially filled with fluid 188, except for the float 190. The float 190 is a small, rigid, and preferably transparent sphere with a small mark 191 (e.g., a dot). The mark 191 is centered within the float 190 so that the float 190 has spherical symmetry relative to the mark 191. The float 190 is also preferably hollow. It has a lower density than the surrounding fluid 188, and the float 190 rises to the relative top of the fluid 188 depending on the orientation of the square 160. In other embodiments of the bubble level 180, the float 190 may instead be a simple bubble in the fluid 188.

[0114] The bubble level 180 includes various indications. The bubble level 180 has a bullseye formed by a horizontal line 192 and a vertical line 193 at right angles to the horizontal line, the horizontal line 192 and the vertical line 193 each extending completely across the diameter of the side wall 183 on both sides and passing through the top 189 of the side wall 183. The horizontal line 192 is parallel to the first edge 13", and the vertical line 193 is parallel to the second edge 14". The circular line 194 is located at the center of the intersection of the horizontal line 192 and the vertical line 193. When the square 160 is laid flat (such as Figure 6194) so ​​that when its second side 171 is against the horizontal surface, the float 190 rises to the top 189 and rests somewhere inside or near the circular line 194. This tells the metalworker how close to horizontal the horizontal surface actually is. If the float 190 touches part of the circular line 194, then the horizontal surface is off horizontal, for example by 2% or another value. If the float 190 is further outside the circular line 194, then the horizontal surface is off further.

[0115] The bubble level 180 also allows the metalworker to check any angle of the surface. Radial hash marks 195 are scored on the ring of sidewall 183 just inside the inner wall 182 of bracket 181. Hash marks 195 are angular measurements where a zero degree angle corresponds to a hash mark 195 at the end of a vertical line 193, which is located proximal to the second corner 17". Figure 5 , the float 190 has risen toward this zero degree angle, indicating that the first edge 13" is horizontal. If the first edge 13" were resting on a surface at an angle of, for example, seventeen degrees, then the float 190 would rise to the hash mark 195 corresponding to seventeen degrees (or the space between the hash marks corresponding to sixteen and eighteen degrees, or some other space between the hash marks on the seventeen degree side).

[0116] exist Figure 5 and 6 In the embodiment shown in , the bubble level 180 occupies most of the middle portion of the body 161 of the square 160. Due to the size of the bubble level 180, the square does not include the middle slit 22, the second slot 30, the laser 80, or the fixture block 81. However, in other embodiments, the bubble level 180 is smaller or larger, depending on the needs of the specific implementation and the work to be done with the square 160. And in such other embodiments, the square 160 includes the middle slit 22, the second slot 30, the laser 80, the fixture block 81, or some combination of those elements. In fact, other carpenter's squares according to the scope of the present disclosure may include other bubble levels described herein. The scope of the present disclosure and the described embodiments includes all permutations of the various structural elements and features of all embodiments disclosed herein.

[0117] Figure 7A carpenter's square 210 is illustrated. The square includes a body 211 having three edges. Square 210 has: 1) a bevel edge 212 opposite a welder's corner 215; 2) a first short edge 213 extending between welder's corner 215 and a first corner 216 formed by and between first short edge 213 and bevel edge 212; and 3) a second short edge 214 extending between welder's corner 215 and a second corner 217 formed by and between second short edge 214 and bevel edge 212. These three edges cooperate to define a perimeter edge 218 of the body 211 of square 210 itself.

[0118] The guide plate 219 is pivotally connected to the bevel edge 212. The guide plate 219 is a generally rectangular piece of material coextensive with the bevel edge 212. The guide plate 219 is preferably pivotally connected between three indexed positions. Figure 7 In the embodiment shown in dashed lines in FIG. 1 , the guide plate 219 is orthogonal to the main body 211 in a first direction (upward along the paper surface, or toward the top of the page). In the second position of the guide plate 219 (also shown in dashed lines in FIG. 1 ), the guide plate 219 is orthogonal to the main body 211 in a first direction (upward along the paper surface, or toward the top of the page). Figure 7 In the third position (shown in dashed lines), the guide plate 219 is orthogonal to the main body 211 in a second direction opposite to the first direction (downward along the paper, or toward the bottom of the page). Figure 7 In the figure (shown by solid lines), the guide plate 219 is coplanar with the main body 211.

[0119] As with the guide plate 19 of the square 10, when the guide plate 219 is in the first or second position, the carpenter can place the guide plate 219 against the straight edge and mark the line. The arrangement of the guide plate 219 orthogonal to the body 211 of the square 210 facilitates quick alignment of the square 210. However, if the carpenter wishes to place the body 211 of the square 210 completely on the workpiece and at least partially inside the straight edge, he only needs to move the guide plate 219 to the third position so that the guide plate 219 is aligned coplanar with the body 211 and the entire square 210 can be placed flat on the workpiece.

[0120] The body 211 of the square 210 is generally triangular in shape, as the perimeter edge 218 generally has three major sides or lengths. The first and second edges 13 and 14 intersect at a welder corner 215, the first edge 213 and the bevel edge 212 intersect at an acute first corner 216, and the second edge 214 and the bevel edge 212 intersect at an acute second corner 217.

[0121] The first and second edges 213 and 214 are orthogonal to each other and almost intersect at a welder's angle 215. The welder's angle 215 is a notch or open angle formed by the diagonal edges between the first edge 213 and the second edge 214. The welder's angle 215 defines an open space just outside the body 211 of the square 210 that can receive a weld between two metal sheets. In other words, a metalworker can place the square 210 against two metal sheets arranged orthogonally to each other, and if the welder's angle 215 is placed over the weld between the two metal sheets, the square 210 is flush with the two metal sheets. This allows a metalworker to use the square 210 in situations where the weld would prevent other carpenter's angles from fitting snugly. One of ordinary skill in the art will recognize that because the first and second edges 213 and 214 are orthogonal to each other, the welder's angle still defines a right angle. The diagonal edge 220 is part of the peripheral edge 218 but is extremely short and small so that the three main sides of the edges 212, 213 and 214 dominate the appearance of the square 210, making the body 211 overall triangular.

[0122] The body 211 is preferably constructed of a material or a combination of materials having strong, sturdy, durable and rigid material properties. Preferably, the body 211 is made of metal, hardwood, plastic or a similar material that provides these properties.

[0123] The main body 211 has a first surface 221 and an opposite second surface 222 ( Figure 7 The first and second faces 221 and 222 are flat and parallel to each other, separated by a width Z of the body 211. The first and second faces 221 and 222 are marked with a plurality of indications and measurements. In addition, slots and slits are formed from the first face 221 completely through the body 211 to the other second face 222. For example, in Figure 7 In the embodiment shown in , two slots are formed on the inner sides of the first and second edges 213 and 214 .

[0124] The first slot 223 is parallel to and inside the second edge 214. The first slot 223 has opposing major sides 224 and opposing diagonal minor ends 225. The major sides 224 are both parallel to the second edge 214, and the major sides 224 at the proximal end of the second edge 214 are larger than the major sides 224 at the distal end of the second edge 214. The minor ends 225 are diagonal and point inward at approximately forty-five degrees, such that the minor ends 225 at the proximal end of the first edge 213 are inclined away from the first edge 213 and the minor ends 225 at the distal end of the first edge 213 are inclined toward the first edge 213. Thus, the first slot 223 has the appearance of an isosceles trapezoid. The first slot 223 is open so that a pencil can be passed through it to mark a workpiece below, especially when the square 210 is slid along the workpiece. Along the major sides 224 of the second edge 214 at the proximal end of the square 210, the first face 221 is marked with measurement indicators 226. Here, the measurement indicator 226 is a one and a half inch mark measured from the second edge 214. Since the first slot 223 is offset from the first edge 213, the first of the measurement indicators is a one inch mark because the end of the first slot 23 proximal to the first edge 213 is one inch away from the first edge 213. In other embodiments, the first slot 223, if present, has other shapes, orientations, and arrangements.

[0125] Another slot (bevel slot 230) is formed inside the bevel edge 212. Bevel slot 230 is parallel to and inside the bevel edge 212. Bevel slot 230 has opposing major sides 231 and opposing diagonal minor ends 232. Major sides 231 are both parallel to bevel edge 212, and major sides 231 proximal to bevel edge 212 are larger than major sides 231 distal to bevel edge 212. Minor ends 232 are diagonal and point inward at approximately forty-five degrees, such that minor ends 232 proximal to first edge 213 are parallel to first edge 213 and minor ends 232 proximal to second edge 214 are parallel to second edge 214. Thus, bevel slot 230 has the appearance of an isosceles trapezoid. Bevel slot 230 is also open so that a pencil can be passed through it to mark a workpiece below. Along both major sides 231, first face 221 is marked with measurement indicators 233. In other embodiments, the beveled slots 230 (if present) have other shapes, orientations, and arrangements.

[0126] Similar to the guide plate 19, the guide plate 219 is hinged to the body 211 to move between three indexed positions. Although in other embodiments, the guide plate 219 is pivoted between an alternative number of positions, for ease and clarity of understanding, the embodiment shown herein is pivoted between three positions. After reading this description, a person of ordinary skill in the art will readily understand how the guide plate 219 moves among an alternative number of positions in such other embodiments.

[0127] The guide plate 219 has a body 240 that is generally in the form of a rectangular prism and extends between two opposing ends 241 and 242. The ends 241 and 242 are flat and parallel to each other and are both oriented at a forty-five degree angle to each of the first and second edges 213 and 214. The body 240 of the guide plate 219 includes a narrow guide plate edge 243 extending between the two ends 241 and 242. The guide plate edge 243 is straight and is not interrupted by notches, protrusions, indentations, or other features that would prevent the guide plate edge 243 from defining a straight line. The body 240 includes an inner edge 244 that points to the first edge 213 of the body 211 of the square 210, opposite the guide plate edge 243. Like the first edge 213, the inner edge 244 is interrupted by a hinge assembly that couples the guide plate 219 to the body 211 of the square 210. The first edge 213 and the inner edge 244 are both slightly rounded so that the guide plate 219 can be smoothly pivoted relative to the body 211 without interruption or jamming.

[0128] The body 240 of the guide plate 219 has first and second faces 245 and 246. The faces 245 and 246 are flat and parallel to each other, separated by the same width Z, which defines the width of the body 211 of the square 210. When the guide plate 219 is arranged in its third position, the first face 245 of the guide plate 219 is aligned and coplanar with the first face 221 of the body 211, and the second face 246 is aligned and coplanar with the second face 221 of the body 211. The first and second faces 245 and 246 are both marked with measurement indicators 247 along the guide plate edge 243. The measurement indicators 247 on the first and second faces 245 and 246 are identical, starting from the second end 242 and increasing in number toward the opposite end 241. The guide plate edge 243 also carries a measurement indicator that is aligned with the measurement indicator 247. However, while the measurement indicators 247 preferably include ticks or hash marks as well as numbers, due to the limited space available on the guide edge 243, the measurement indicators on the guide edge 243 preferably include only hash marks, similar to those on the guide edge 43 of the square 10. A carpenter can easily see the numbers on the adjacent first or second face 245 or 246 to identify the measurement.

[0129] The guide plate 219 is preferably mounted to the body 211 of the square 210 at two hinge assemblies 250 (including structural features and elements on both the guide plate 219 and the body 211). In fact, the guide plate 219 is mounted to the body 211 of the square 210 in the same manner as the guide plate 19 of the square 10 is mounted to the body 11, except that the guide plates 19 and 219 are mounted to different edges, the first edge 13 and the bevel edge 212, respectively. The two hinge assemblies 250 are identical in structure and differ only in position, and thus, the reader will understand that the description of this hinge assembly 250 is equally applicable to the description of the other hinge assembly 250. Reference numerals are marked on any one of the hinge assemblies 250 to prevent cluttering the drawings. In other embodiments, there may be fewer or more hinge assemblies 250.

[0130] Inside the beveled edge 214, a notch 252 interrupts the first edge 213. The notch 252 is concealed and extends into the body 211 of the square 210, terminating at an inner wall extending between two sides 253 and 254 of the notch 252. The notch 252 defines a receiving space complementary to a tab 255 on the guide plate 219, which fits onto the notch 252.

[0131] The tab 255 is an integral, one-piece, monolithic protrusion of the body 240 at the inner edge 244 of the guide plate 219. The tab 255 has two opposing ends 256 and 257 orthogonal to the inner edge 244 and an inner edge 258 extending between the ends 256 and 257. Like the inner edge 244 of the guide plate 219 itself, the inner edge 258 is rounded. The distance between the ends 256 and 257 is approximately half to two-thirds of the distance between the sides 253 and 254 of the notch 252, and therefore the tab 255 fits easily within the notch 252.

[0132] The tab 255 is mounted on a pin or shaft 260. Preferably, the hole 61 extends completely through the tab 255 between the ends 256 and 257 of the tab 255. The shaft 260 is mounted between the sides 253 and 254 of the notch 252 and is snugly received in the hole 261 so that the tab 255 and the guide plate 219 connected thereto are mounted for pivotal movement about an axis defined by the shaft 260. A compression spring 262 is mounted over the shaft 260 and is compressed between the end 256 of the tab 255 and the side 253 of the notch 252. The compression spring 262 biases the tab 255 toward the other side 254 of the notch 252, which is defined as the neutral position. In the neutral position, the end 257 of the tab 255 is in contact with the side 254 of the notch 252. In the neutral position, the guide plate 219 maintains coextensive alignment with the body 211 of the square, as shown in FIG. Figure 7 As shown in ; end 241 is aligned with the first angle 216, and end 242 is aligned with the second angle 217.

[0133] The tab 255 can be moved out of this neutral position into a forward position. The forward position is not shown, but the user is reading about Figures 2A to 2D After describing the movement of the tab 55 of the square 10, it will be understood that the following discussion is similar. To move the tab 255 out of the neutral position and into the forward position, the carpenter simply grasps the body of the guide plate 219 and moves along the bevel edge 213 of the square 210, along the Figure 7 Slide the guide plate 219 upward along the arrow line S" in FIG. Sliding the guide plate 219 in this manner compresses the spring 262 between the end 256 and the side 253, and therefore the carpenter must use force to move the guide plate 219 to the forward position.

[0134] The engagement assembly prevents the tab 255 from accidentally moving out of the third position. When the tab 255 is in the neutral position while in the third position, the engagement assembly prevents the guide plate 219 from moving into the first or second position. The guide plate 219 can only move to the first or second position when the tab 255 is in the advanced position. Figure 7 25, the groove 264 depends slightly into the second face 222 of the body 211. The groove 264 communicates with the notch 252, extending from the notch 252 across the second face 222 of the body 211 toward the second edge 214. The same groove extends into the first face 221 on the other side of the body 211, and another identical groove is formed into the first edge 213 itself. The grooves are individually and collectively identified with the reference numeral 264, and the reader will understand their structure, location and function from the description of similar grooves 63 to 65. Each of the grooves 264 is a generally semi-cylindrical cavity.

[0135] A tongue 266 complementary to the groove 264 is carried on the guide plate 219 and is Figure 7 244 of the guide plate 219. The tongue 266 has a longitudinal axis parallel to the first edge 213 of the guide plate 219. The tongue 266 has a proximal end that is integrally and monolithically formed with the end 257 of the tab 255, and the tongue 266 extends along the first edge to the distal end, thereby presenting a semi-cylindrical convex surface outwardly between the proximal and distal ends. The tongue 266 is sized and shaped to be received within each of the grooves 264 formed in the body 211 of the square 210. Except for the position on the square 210, the tongue 266 and the grooves 264 are aligned with the square 210. Figures 2A to 2D The tongue 66 and grooves 63 to 65 shown in FIG. 6 are identical, and Figures 2A to 2D The accompanying drawings together with this description should enable a person of ordinary skill in the art to understand the structure and position of the tongue 266 and the groove 264.

[0136] As the tab 255 moves among the first, second, and third positions of the guide plate 219, the tongue 266 moves in and out of the groove 264 to temporarily lock the guide plate 219 in the first, second, and third positions. When the guide plate 219 is in the first position, the groove 264 in the first face 221 receives the tongue 266, and the interaction of the tongue 266 with that groove 264 prevents the guide plate 219 from pivoting relative to the body 211. When the guide plate 219 is in the second position, the groove on the second face 222 receives the tongue 266, and the interaction of the tongue 266 with that groove 264 prevents the guide plate 219 from pivoting relative to the body 211. And when the guide plate 219 is in the third position, the groove 264 on the bevel edge 212 receives the tongue 266, and the interaction of the tongue 266 with that groove 264 prevents the guide plate 219 from pivoting relative to the body 211.

[0137] When the guide plate 219 is in each of the first, second and third positions, if the carpenter attempts to pivot the guide plate 219 to another position, the tongue 266 contacts the side of the corresponding groove and is prevented from pivoting. Therefore, each time the tongue 266 is received in one of the grooves 264, the guide plate 219 cannot move unless the tab 255 is first moved out of the neutral position. Thus, in this embodiment, the first, second and third positions of the guide plate 219 are defined, discrete and indexed positions. In this embodiment, the guide plate 219 can only be placed and temporarily locked into one of these positions. Other embodiments have fewer or more positions (indexed or otherwise). The guide plate 219 is temporarily locked because it is effectively prevented from being accidentally or accidentally moved out of the position, but the carpenter can easily and purposefully move the guide plate 219 out of the position by sliding the guide plate 219 upward into the forward position of the tab 255. Thus, the tongue 266 and the groove 264 define an engagement assembly or spring pawl assembly for locking and releasing the guide plate 219 .

[0138] When the carpenter desires to move the guide plate 219 into another position (e.g., from the third position to the first position), he first slides the tab 255 out of the neutral position and into the advanced position. This causes the tongue 266 to slide longitudinally out of the groove 264 in the bevel edge 212. The spring 262 applies a bias on the tab 255 to return it to the neutral position, and therefore the carpenter must hold the guide plate 219 to prevent it from returning to the neutral position. While still grasping the guide plate 219 in the advanced position, the carpenter pivots the guide plate 219 to that side. When so pivoted, the tongue 266 is in register with the groove 264 but is longitudinally offset from the groove 264. The carpenter can then release the guide plate 219 and allow the spring 262 to bias the guide plate 219 back to the neutral position in the direction opposite to the arrow line S". When the guide plate 219 moves back to the neutral position, the tongue 266 is received by and engages with the groove 264 on the first face 221. The guide plate 219 is now temporarily locked into the first position.

[0139] The guide plate 219 is preferably made of the same material as the body 211 of the square 210. In some embodiments, the guide plate 219 includes magnetic elements 267, examples of which are shown in phantom in three locations in the guide plate 219. Figure 7 The magnetic elements 267 shown in FIG. 2 are circular, disc-shaped magnets and are enclosed within the body 240 of the guide plate 219. In other embodiments, the magnetic elements 267 may be offset within the body 240 or flush with one of the first or second faces 245 and 246. The embodiment shown herein has three magnetic elements 267 spaced along the length of the guide plate 219. The magnetic elements 267 are useful for aligning and holding a square during metalworking. Some embodiments of the guide plate 219 have fewer magnetic elements 267 than shown herein, some embodiments have more magnetic elements 267, and some embodiments have no magnetic elements 267 at all.

[0140] Square 210 has a dual measurement system. Two different measurements can be made along first edge 213. First edge 213 has two sets of measurement indicators. A first set 271 of measurement indicators are marked along first edge 213. This first set 271 is Figure 7 271 are identifiable in the figure because the measurement numbers (1, 2, 3, etc.) are oriented with their tops toward the left in the figure. The first group 271 has a zero position from which the remaining indicators in the first group 271 are measured and to which the first group 271 corresponds. This zero position corresponds to the intersection of the lines that are aligned with the first and second edges 213 and 214 in the welder corner 215.

[0141] Alternatively, the second set 272 of measurement indicators are marked along the first edge 213. The second set 272 has a zero position 274 from which the remaining indicators in the second set 272 are measured and to which the second set 272 corresponds. This zero position 274 corresponds to the intersection of the first edge 213 and the diagonal edge 220.

[0142] The first and second groups 271 and 272 of measurement indicators share the same hash mark 275. Thus, depending on the arrangement of the guide plate 219, the hash mark 275 can be read with the first or second group 271 and 272 of measurement indicators. However, the numbering indicia of the first and second groups 271 and 272 are different. The second zero position 274 is offset from the first zero position, and therefore the numbering indicia of the second group 272 of measurement indicators is offset from the first group 272 of measurement indicators.

[0143] Like squares 10 and 160, square 210 preferably carries a bubble level 280, but bubble level 280 is different from bubble levels 82 and 180. Bubble level 280 is one embodiment of a bubble level, although it shares many similarities with bubble level 180.

[0144] The bubble level 280 has a central hub similar to the bubble level 180, but has a half ring around the hub instead of a full ring. The float floats freely between the hub and the half ring depending on the orientation of the square 210. The bubble level 280 is set into a bracket 281 in the body 211 of the square 210. The bracket 281 is a hole formed from the first face 221 through the body 211 to the second face 221. The bubble level 280 fits tightly into the bracket 281, but in some embodiments, the bubble level 280 is fixed in the bracket 281 not only by a tight fit but also by an adhesive or some other fastener.

[0145] The bubble level 280 is formed by a thin side wall 283, which is preferably symmetrical about a central axis parallel to the first and second faces 221 and 222. The side wall 283 has an upper wall (eg Figure 7 284, but similar to first wall 184 of bubble level 180) and a lower wall (below the upper wall, similar to second wall 185 of bubble level 180), which are preferably symmetrical to each other. The upper and lower walls intersect at the inner wall of bracket 281. The upper and lower walls extend radially inward from the inner wall, expanding outward away from each other until an inflection point 286. Inflection point 286 is a generally circular boundary between the ring (outside inflection point 286) and the hub (inside inflection point 286). Within inflection point 286, the upper and lower walls each define a truncated or cut-off sphere having only a circular portion that is less than a hemisphere. The upper and lower walls cooperate together to define a generally egg-shaped space at the hub within inflection point 286. In other embodiments, this hub has other shapes.

[0146] Within the inflection point 186, both the first and second walls 184 and 185 rise to a top 289 that is flush with or just inside the first and second faces 221 and 222, respectively. Thus, the bubble level 280 is bounded within the body 211 by the first and second faces 221 and 222. In other embodiments, the hub or top 289 may extend beyond these first and second faces 221 and 222, but in such other embodiments, the bubble level 280 may be scratched and damaged.

[0147] The sidewall 283 is preferably transparent so that a metal worker can view the bubble level 280 from either side of the square 210 and observe the interior 287 of the bubble level 280. The interior 287 is substantially filled with fluid except for the float 288. The float 288 is a small, transparent, and rigid sphere or capsule with a small mark 285 (e.g., a dot). The mark 285 is centered within the float 288 so that the float 288 has spherical symmetry relative to the mark 285. In addition, the float 288 is preferably hollow. It has a lower density than the surrounding fluid, and the float 288 rises to the relative top of the fluid depending on the orientation of the square 210. In other embodiments of the bubble level 280, the float 288 can instead be a simple bubble in the fluid.

[0148] Unlike bubble level 180, bubble level 280 is cut and incomplete. Instead of sidewall 283 extending completely around in a continuous full circle, two interrupted edges 290 and 291 cut the ring, each extending inward from the perimeter of bubble level 280 to meet at an angle offset from the center of bubble level 280. This angle is preferably generally pointed toward welder corner 215. Edges 290 and 291 preferably do not pass through top 289.

[0149] The bubble level 280 includes various indications. The bubble level 280 has a bull's eye formed by a horizontal line 292 and a vertical line 293 at right angles to the horizontal line, each extending completely across the diameter of the side wall 183 on both sides and through the top 289 of the side wall 183. The horizontal line 292 is parallel to the bevel edge 212, and the vertical line 293 is orthogonal to the bevel edge 212. The circular line 294 is centered at the intersection of the horizontal line 292 and the vertical line 293. When the square 210 is laid flat so that its second face 221 is against a horizontal surface, the float 288 rises to the top 289 and rests somewhere inside or near the circular line 294. This tells the metalworker how close the horizontal surface actually is to horizontal. If the float 288 touches part of the circular line 294, then the horizontal surface is off horizontal, for example by 2% or another value. If the float 288 is farther outside the circular line 294, then the horizontal surface is off further.

[0150] The bubble level 280 also allows the metalworker to check any angle of the surface. Radial hash marks 295 are scored on the ring of the sidewall 283 just inside the inner wall of the bracket 281. The hash marks 295 are angular measurements where the zero degree angle corresponds to the hash mark 295 at the end of the vertical line 293, which is located proximal to the second angle 217. If the first edge 213 is placed on a surface at an angle of, for example, seventeen degrees, then the float 288 will rise to the hash mark 295 corresponding to seventeen degrees (or the space between the hash marks 295 corresponding to sixteen and eighteen degrees, or some other space between the hash marks 295 on the seventeen degree side).

[0151] In the embodiment shown herein, the bubble level 280 occupies a majority of the middle portion of the body 211 of the square 210. Due to the size of the bubble level 280, the square 210 preferably does not include the middle slit 22, the second slot 30, the laser 80, or the fixture block 81. However, in other embodiments, the bubble level 280 is smaller or larger, depending on the needs of the particular implementation and the work to be done with the square 210. And in such other embodiments, the square 210 includes the middle slit 22, the second slot 30, the laser 80, the fixture block 81, or some combination of those elements. The scope of the present disclosure and described embodiments includes all permutations of the various structural elements and features of all embodiments disclosed herein.

[0152] Figures 8 to 10B A carpenter's level 310 is illustrated. The carpenter's level 310 is an example of any of several elongated levels, such as a box level, a mason's level, a torpedo level, a column level, and other similar levels. Here, the carpenter's level 310 is relatively long (e.g., four feet long), but in other embodiments is only a few inches long or eight feet long.

[0153] The carpenter's level 310 comprises a frame 311 carrying a circular bubble level 312 and two square bubble levels 313. The carpenter's level 310 is useful for finding horizontal, vertical and all measurement angles.

[0154] The frame 311 is elongated, extending between two opposite ends 320 and 321 which are preferably blunt and parallel to each other. The frame 311 has long top and bottom edges 322 and 323, and long front and back faces 324 and 325. The back face 325 is Fig. 9B But in Figure 8 The top and bottom edges 322 and 323 are orthogonal to the ends 320 and 321 and the faces 324 and 325. The ends 320 and 321, the top and bottom edges 322 and 323, and the front and back faces 324 and 325 cooperate to give the frame 311 a generally box-like or rectangular prism appearance.

[0155] The frame 311 includes three brackets: a first or left bracket 331, a second or right bracket 332, and a third or middle bracket 333. The brackets 331, 332, and 333 are gaps in the frame 311 that receive and hold the bubble levels 312 and 313. The bracket 331 is located near the end 320 and is referred to as the left bracket 331 for convenience only, without limiting the scope of the present disclosure. The bracket 332 is located near the other end 321 and is referred to as the right bracket 332 for convenience only, without limiting the scope of the present disclosure. The bracket 333 is located in the middle position between the ends 320 and 321, preferably but not necessarily in the middle between the ends 320 and 321. Calling it the middle bracket 333 is just for convenience and does not limit the scope of the present disclosure.

[0156] Fig. 9A 3 is an enlarged view of the circular bubble level 312 disposed into the intermediate bracket 333. The bubble level 312 is circular in shape and includes an annular perimeter tube and a plurality of hash marks to indicate the relative angular displacement of the box level 310.

[0157] refer to Fig. 9A and Fig. 9B Both, bubble level 312 includes a tube 340 surrounding a middle portion 341. Float 342 moves around tube 340 to a highest position, and markings 343 on middle portion 341 allow a carpenter to identify the angular displacement of box level 310.

[0158] Tube 340 has a thin side wall 344 that is preferably symmetrical about a central axis extending orthogonally through box level 310. Side wall 344 is preferably transparent and preferably circular in cross section, such as Fig. 9B In other embodiments, the sidewall 344 has other shapes and configurations. The outer diameter of the sidewall 344 is equal to or less than the thickness of the frame 311 between the front and back surfaces 324 and 325, so that the sidewall 344 is less likely to be scratched by surface contact on the front and back surfaces 324 and 325.

[0159] Sidewall 344 delimits and defines an annular interior 345 of bubble level 312. In addition to float 342, interior 345 is substantially filled with fluid 346. Float 342 is a small, rigid and preferably transparent sphere with a small mark 347 (e.g., a dot). Mark 347 is centrally located within float 342 so that float 342 has spherical symmetry relative to mark 347. In addition float 342 is preferably hollow. It has a lower density than the surrounding fluid 346, and float 342 rises to the relative or local top of fluid 346 depending on the orientation of box level 310. In other embodiments of bubble level 312, float 342 can instead be a simple bubble in fluid 346.

[0160] The tube 340 surrounds the middle portion 341. The middle portion is a disk-shaped solid frame element that is located within the tube 340. Like the frame 311 of the level 310, it has opposing front and back faces 350 and 351. The front and back faces 350 and 351 are preferably coplanar with the corresponding front and back faces 324 and 325 of the frame 311, so that the middle portion 341 has the same thickness as the frame 311. In other embodiments, the middle portion 341 is thinner than the frame 311, and the front and back faces 350 and 351 are thinner than the frame 311. Fig. 9B The ones drawn in are closer together.

[0161] The middle portion 341 has a perimeter 352 that contacts the inside of the tube 340. Along the perimeter and on the front and back faces 350 and 351, the middle portion 341 is marked with markings 343. The markings 343 include radial hash marks 353 scored into or on the front and back faces 350 and 351 just inside the perimeter 352. The hash marks 353 are angle measurements, with a zero degree angle corresponding to two opposing hash marks 353 proximal to the top and bottom edges 322 and 323. Some of the hash marks 353 are marked with a numerical reference 354 so that a carpenter can quickly and easily identify the angle.

[0162] exist Figure 8 In the embodiment shown in FIG. 3 , the bubble level 312 occupies a central position in the box level 310. In other embodiments, it may be located in other parts of the box level 310. Or, it may be swapped with the square level 313.

[0163] Fig. 10A 310. is an enlarged view of a square bubble level 313 disposed in the first bracket 331 proximal to the end 320. The square bubble level 313 in the second bracket 332 is identical in every respect to the bubble level 313 in the first bracket 331 except for the position. Thus, this description will be made only with respect to the bubble level 313 in the first bracket 331, with the understanding that the same applies to the bubble level 313 in the second bracket 332. The bubble level 313 is generally square in shape and includes an annular perimeter tube and a plurality of hash marks to indicate relative angular displacement of the box level 310.

[0164] refer to Fig. 10A and Fig. 10B Both, bubble level 313 includes a tube 360 ​​surrounding a middle portion 361. A float 362 moves around tube 360 ​​to a highest position, and markings 363 on tube 360 ​​allow a carpenter to identify the angular displacement of box level 310. Tube 360 ​​is generally square in shape and has four sections 360a, 360b, 360c, and 360d.

[0165] Tube 360 ​​has a thin side wall 364 which is preferably transparent and preferably elliptical in cross section, such as Fig. 10B In other embodiments, the sidewall 364 has other shapes and configurations. The sidewall 364 has a size equal to or less than the thickness of the frame 311 between the front and back faces 324 and 325, so that the sidewall 364 is less likely to be scratched by surface contact on the front and back faces 324 and 325.

[0166] Sidewall 364 delimits and defines a generally square interior 365 of bubble level 313. In addition to float 362, interior 365 is substantially filled with fluid 366. Float 362 is a small, rigid and preferably transparent sphere or disk with a small mark 367 (e.g., a dot). Mark 367 is centrally located within float 362 so that float 362 has symmetry relative to mark 367. In addition float 362 is preferably hollow. It has a lower density than the surrounding fluid 366, and float 362 rises to the relative or local top of fluid 366 depending on the orientation of box level 310. In other embodiments of bubble level 313, float 362 can instead be a simple bubble in fluid 366.

[0167] Tube 360 ​​surrounds middle portion 361. Tube 360 ​​has a continuous inner edge 370 and an opposing continuous outer edge 371 that delimits middle portion 361. Continuous inner edge 370 is square: it includes four linear edges of equal length, each linear edge is parallel to one other linear edge and is orthogonal to two other linear edges. This defines middle portion 361 as a square element. However, continuous outer edge 371 is only approximately square. Outer edge 371 bulges outward slightly between the four corners of outer edge 371. Although float 362 is in Fig. 10A The angle 360 ​​appears large in the illustration, but is large enough so that the float 362 can move between the four sections 360a to 360d of the tube 360 ​​without obstruction. Fig. 10B The preferred size of the float 362 is more clearly shown without enlarging the transparent side wall 364.

[0168] The float 362 moves freely throughout the bubble level 313 in response to the movement of the box level 310. Each of the four sections 360a to 360d of the square bubble level 313 has two spaced apart marks 363 in a horizontal line. Sections 360a and 360c are parallel to the top and bottom edges 322 and 323, and sections 360b and 360d are parallel to the ends 320 and 321. In each section 360a to 360d, the outer edge 371 is farthest from the inner edge 370 between the marks 363, so that the marks 363 represent the local top of each section 360a to 360d. The distance between the marks 363 is just greater than the outer dimension of the float 362. When the top or bottom edge 322 or 323 is placed against the object and the float 362 is between the markings 363 in the section 360c or 360a, respectively, the bubble level 313 indicates that the surface of the object has a certain measurement, such as level. However, if the float 362 contacts one of the markings 363, then the surface of the object deviates from that measurement, such as by 2% or another value. And if the float 362 is farther outside the markings 363, then the surface of the object deviates even farther from that measurement.

[0169] The middle portion 361 is a solid square frame element that is located within the tube 360. Like the frame 311 of the level 310, it has opposing front and back faces 372 and 373. The front and back faces 372 and 373 are preferably coplanar with the corresponding front and back faces 324 and 325 of the frame 311, so that the middle portion 361 has the same thickness as the frame 311. In other embodiments, the middle portion 361 is thinner than the frame 311, and the front and back faces 372 and 373 are thinner than the frame 311. Fig. 10B The ones drawn in are closer together.

[0170] exist Figure 8 , the bubble level 313 occupies a position proximal to the ends 320 and 321 of the box level 310. In other embodiments, either or both of the levels 313 may be located in other portions of the box level 310. Or, they may be swapped with the circular level 312. Furthermore, it should be understood that the bubble levels 312 and 313 may be incorporated into the carpenter's squares 10, 110, 160, and 210 described above by replacing or adding the level features in those squares, and such incorporation is considered to be within the scope of the present disclosure. Furthermore, the levels and other features (such as lasers or jigs) described with respect to the carpenter's squares 10, 110, 160, and 210 may be incorporated into the box level 310 (or other similar levels, such as box levels, masons levels, torpedo levels, column levels, and other similar levels) without departing from the scope of the present disclosure. The scope of the present disclosure and described embodiments includes all substitutions of the various structural elements and features of all embodiments disclosed herein.

[0171] Figures 11A to 12G Example

[0172] Figures 11A to 12G Another embodiment of a carpenter's square 410 (hereinafter referred to as "square 410") is described. Square 410 is similar to the above-described embodiments (including square 10). Therefore, many of the reference numerals used for other embodiments are also used here to identify the same or similar structural elements or features. For example, square 410 includes a body 11 having three edges. Square 410 has: 1) a bevel edge 12 opposite a right angle 15; 2) a first short edge 13 extending between right angle 15 and a first corner 16, the first corner 16 being formed by and between the first short edge 13 and the bevel edge 12; and 3) a second short edge 14 extending between right angle 15 and a second corner 17, the second corner 17 being formed by and between the second short edge 14 and the bevel edge 12. These three edges cooperate to define a perimeter edge 18 of the body 11 of square 410 itself. Not all of the structural elements and features of square 410 are described, as the reader is already familiar with those structural elements and features from the rest of this description.

[0173] The guide plate 411 is pivotally connected to the first edge 13. The guide plate 411 is a generally rectangular piece of material coextensive with the first edge 13. The guide plate 411 is preferably pivotally connected between three indexed positions similar to the indexed positions of the guide plate 19: a first position in which the guide plate 411 is orthogonal to the body 11 in a first direction; a second position in which the guide plate 411 is orthogonal to the body 11 in a second direction opposite to the first direction; and a third position in which the guide plate 411 is coplanar with the body 11. These positions correspond to the following: Figure 1C 1 , 2 and 3 positions of the angle square 10 are shown.

[0174] When the guide plate 411 is in either the first or second position, the carpenter can lay most of the square 410 flat on the surface while the guide plate 411 is against the straight edge and can mark the line on the surface. The arrangement of the guide plate 411 orthogonal to the body 11 of the square 410 makes it easy to quickly align the square 410. However, if the carpenter desires to place the straightedge 410 completely on the workpiece and inside the straight edge, he only needs to move the guide plate 411 to the third position so that the guide plate 411 is aligned coplanar with the body 11 and the entire straightedge 410 can be laid flat on the workpiece.

[0175] The body 11 of the square 410 is triangular in shape overall because the perimeter edge 18 has three major sides or lengths overall. The first and second edges 13 and 14 meet at a right angle 15, and the second edge 14 and the hypotenuse edge 12 meet at an acute second corner 17. The first edge 13 and the hypotenuse edge 12 meet at a first corner 16, which is an acute angle but is blunted or truncated by a fourth short edge. Thus, the perimeter edge 18 technically has four sides or four edges, but the very short side at the first corner 16 is so small that the three major sides of the edges 12, 13 and 14 dominate the appearance of the square 410, making the body 11 triangular in shape overall. Thus, the square 410 has, in a way, a triangular body 11 defined by the perimeter edge 18 with four sides.

[0176] The body 11 is preferably constructed of a material or a combination of materials having strong, sturdy, durable and rigid material properties. Preferably, the body 11 is made of metal, hardwood, plastic or a similar material that provides these properties.

[0177] The body 11 has a first face 420 and an opposing second face 421. The faces 420 and 421 are flat and parallel to each other, separated by the width of the body 11. The faces are marked with a variety of indications and measurements. In addition, slots and slits are formed completely through the body 11 from the first face 420 to the second face 421. As shown in the previous embodiments, the slots and slits can have various arrangements and embodiments, and the slots and slits of those other embodiments are incorporated herein and should be considered to include variations of the embodiments of the square 410 shown herein.

[0178] For example, in the embodiment shown herein, the middle slit 422 extends diagonally through the body 11. The middle slit 422 is linear or straight. The middle slit 422 extends at a substantially forty-five degree angle relative to both the first and second edges 13 and 14, approximately in the middle of those two edges 13 and 14. In other embodiments, the middle slit 422 has other shapes, orientations, and arrangements, and Figures 11A to 11B The embodiment shown in is not limiting. The middle slot 422 may be useful for marking a workpiece beneath the square 410, but may be useful in conjunction with the jig block 81 for designing a cutting pattern, as described with respect to the square 10 embodiment.

[0179] The bevel slot 423 is formed parallel to and inside the bevel edge 12. The bevel slot 423 has opposing major sides 424 and opposing diagonal minor ends 425. The major sides 424 are both parallel to the bevel edge 12, and the major side 424 at the proximal end of the bevel edge 12 is larger than the major side 424 at the distal end of the bevel edge 12. The minor ends 425 are diagonal and point inward at approximately forty-five degrees, so that the minor end 425 at the proximal end of the first edge 13 is parallel to the first edge 13 and the minor end 425 at the proximal end of the second edge 14 is parallel to the second edge 14. Thus, the bevel slot 423 has the appearance of an isosceles trapezoid. The bevel slot 423 is open from the first face 420 to the second face 421, so that a pencil can be passed through it to mark the workpiece below. Along the two major sides 34, the first face 20 is marked with measurement indicators. In other embodiments, the bevel slot 423 (if present) has other shapes, orientations, and arrangements.

[0180] In this embodiment, the square 410 has another slot 426. The slot 426 is parallel to and inside the first edge 13. The slot 426 has opposing major sides 427 and opposing diagonal minor ends 428. The major sides 427 are both parallel to the first edge 13, and the major sides 427 at the proximal end of the first edge 13 are larger than the major sides 427 at the distal end of the first edge 13. The minor ends 428 are diagonal and point inward at approximately forty-five degrees, so that the minor ends 428 at the proximal end of the second edge 14 are inclined away from the second edge 14 and the minor ends 428 at the distal end of the second edge 14 are inclined toward the second edge 14. Therefore, the slot 426 has the appearance of an isosceles trapezoid. In some embodiments, the slot 426 (if present) has other shapes, orientations, and arrangements.

[0181] The slot 426 opens from the first face 420 to the second face 421 so that a pencil can be passed through the slot 426 to mark a workpiece below the slot 426. Along a major edge 427 proximal to the first edge 13 of the square 10, the first face 20 is marked with measurement indicators. In this embodiment, the measurement indicators 429 are shown in English measurements of inches and their graduations measured from the second edge 14. Because the slot 426 is offset from the second edge 14, the first measurement indicator 429 is a two-inch mark. In other embodiments, the measurement indicator 429 is shown in metric measurements. In fact, all markings on the square 410 (or other squares in the present disclosure) can be shown in English, metric, or any other unit measurement.

[0182] The guide plate 411 is hinged to the body 11 to move or swing between three indexed positions. Although in other embodiments, the guide plate 411 is pivoted between an alternative number of positions, for ease and clarity of understanding, the embodiment shown herein is pivoted between three positions. For example, the guide plate 411 can move between one, two, three, four, five or more positions. After reading this description, a person of ordinary skill in the art will readily understand how the guide plate 411 moves among an alternative number of positions in such other embodiments.

[0183] Still refer to Fig.11A and 11B as well as Figures 12A to 12G , the guide plate 411 has a body 430 that is generally rectangular prism-shaped and extends between two opposite ends 431 and 432. The ends 431 and 432 are flat and parallel to each other and are both parallel to the second edge 14. The body 430 of the guide plate 411 includes a guide plate edge 433 extending between the two ends 431 and 432 and pointing away from the body 11 of the square 410. The guide plate edge 433 is straight and is not interrupted by notches, protrusions, indentations or other features that would prevent the guide plate edge 433 from defining a straight line. The body 430 of the guide plate 411 includes an inner edge 434 that points to the first edge 13 of the body 11 of the square 410 opposite the guide plate edge 433. Like the first edge 13 , the inner edge 434 is interrupted by a hinge assembly that pivotally couples the guide plate 411 to the body 11 of the square 410 at the first edge 13 of the body 11 of the square 410 .

[0184] The inner edge 434 has three recesses: a first recess 437, a second recess 438, and a third recess 439. Each of the recesses 437, 438, and 439 is a slight notch formed into the body 430 of the guide plate 411 recessed away from the inner edge 434 thereof.

[0185] The body 430 of the guide plate 411 has a first face 435 and an opposed second face 436. The first and second faces 435 and 436 are flat and parallel to each other, separated by the same width that defines the width of the body 11 of the square 410. When the guide plate 411 is arranged in its third position, the first face 420 of the guide plate 411 is registered and coplanar with the first face 420 of the body 11, and the second face 421 is registered and coplanar with the second face 421 of the body 11. The first and second faces 435 and 436 of the guide plate 411 are both marked with measurement indicators along the guide plate edge 433. The measurement indicators on the first and second faces are identical, starting at the first end 431 and increasing in number toward the opposed end 432. As with the other embodiments, the first and second faces carry two offset measurements along the second edge 14; it is unnecessary to repeat the discussion of those two sets of measurements, and their descriptions are incorporated herein by reference.

[0186] The guide plate 411 is preferably mounted to the body 11 of the square 410 at two hinge assemblies 440 (which include structural features and elements on both the guide plate 411 and the body 11, such as but not limited to notches in the body, recesses in the notches, pins in the notches, tabs on the guide plate, and recesses 437, 438 and 439 on the guide plate 411, as well as various flat surfaces and edges of both the guide plate 411 and the body 11 themselves). The hinge assemblies 440 are structurally identical and differ only in position, and thus, the reader will understand that a description of one hinge assembly 440 is equally applicable to a description of the other hinge assembly 440. In other embodiments, there may be fewer or more hinge assemblies 440.

[0187] The first edge 13 has a flat surface and is square, forming a sharp right angle with both the first and second faces of the body 11. Inside the second edge 14 on the side of the square 10, a notch 441 interrupts the first edge 13. The notch 441 is concealed and rectangular prism-shaped. It extends into the body 11 of the square 410, terminating at an inner wall 442 extending between two opposite sides 443 and 444 of the notch 441. The notch 441 defines a rectangular prism-shaped receiving space larger than the tab 445 on the guide plate 411 that fits into the notch 441. Sharp right angles define all edges of the notch 441 and the tab 445. The notch 441 presents two spaced apart inner faces 446 facing the guide plate 411. The inner faces 446 are flat and at right angles to the first and second faces of the body 11. The inner faces 446 may also be referred to as notch faces.

[0188] The inner faces 446 are separated by a notch 447 which extends from the first edge 13 deeper into the body 11 of the square 410 than the notch 441. The notch 447 is located substantially midway relative to the sides 443 and 444 of the notch 441 and separates the two flat inner faces 446 from each other. The notch 447 thus defines a depression into the body 11 relative to the inner faces 446. The notch 447 corresponds in width to the tabs 445; the distance between the inner faces 446 corresponds to the distance between the ends of the tabs 445.

[0189] The tab 445 is an integral, one-piece, single-piece rectangular prism protrusion of the body 430 of the guide plate 411 at the inner edge 434 of the guide plate 411. The tab 445 has two opposed ends 450 that protrude toward the body 11 of the square 410, orthogonal to the inner edge 434 and to an inner edge 452 extending between the ends. Like the inner edge 434 of the guide plate 411 itself, the inner edge 452 of the tab 445 is flat and at right angles to the first and second faces 435 and 436 of the guide plate 411. The first and second faces 435 and 436 of the guide plate 411 extend over and over the tab 445 and are therefore considered the first and second faces of the tab 445, and the inner edge 452 is considered the third face, all faces being flat.

[0190] The distance between the ends 450 and 451 of the tab 445 is approximately half to two-thirds of the distance between the sides 443 and 444 of the notch 441, and thus the tab 445 can be easily fitted laterally within the notch 441. The distance between the ends 450 and 451 of the tab 445 corresponds to the width of the notch 447, so that the tab 445 can just fit within the notch 447.

[0191] The tab 445 is mounted on a pin or shaft 453. Preferably, a hole extends completely through the tab 445 between the ends 450 and 451 of the tab 445. The shaft 453 is mounted between the sides 443 and 444 of the notch 441 and is snugly received in the hole so that the tab 445 and the guide plate 411 connected thereto are mounted over the shaft 453 and are mounted for both reciprocating movement along the shaft 453 and pivotal movement about an axis defined by the shaft 453. In some embodiments, a compression spring is mounted over the shaft 453 and compressed between one of the ends 450, 451 of the tab 445 and the corresponding side 443, 444 of the notch 441. In such embodiments, the compression spring biases the tab 445 toward the other side of the notch 441. In other embodiments, as shown in these figures, there is no compression spring over the shaft 453.

[0192] Fig.11A and 11B The neutral position of the guide plate 411 is shown. In the neutral position, the tab 445 prevents the guide plate 411 from moving among its three positions. In the neutral position, the inner edge 452 of the tab 445 faces and abuts the inner face 446 of the contact notch 441.

[0193] The first, second and third recesses 437, 438 and 439 are each misaligned or misaligned with the first edge 13, meaning that they at most only partially overlie or oppose the first edge 13. The second recess 438 overlies a portion of the first edge 13 and overlies a portion of one of the indentations 441. The third recess 439 overlies a portion of the first edge 13 and overlies a portion of another of the indentations 441.

[0194] In the neutral position, the guide plate 411 maintains coextensive alignment with the body 11 of the square 410; the end 431 of the guide plate 411 is aligned with the second edge 14 of the square 410, and the end 432 is aligned with the first corner 16. The flat inner edge 452 and the flat inner face 446 face in direct abutting contact, thereby preventing the guide plate 411 from moving relative to the body 11 of the square 410.

[0195] Although the neutral position prevents the guide plate 411 from moving among its three positions, the guide plate 411 can still move out of the neutral position and into the forward position, such as Fig. 12A and 12B In the forward position, the guide plate 411 enables the guide plate 411 to move among its three positions. To move the guide plate 411 and the tab 445 out of the neutral position and into the forward position, the carpenter simply grasps the body of the guide plate 411 and moves along the first edge 13 of the square 410, along the Fig. 12A and 12E The guide plate 411 is slid upward relative to the body 11 of the square 410 by the arrow line S in FIG. The tab is so mounted and reciprocates between the neural posture and the advancing posture along the axis 453 and the arrow line S. In the embodiment where the spring is mounted above the axis 453, the carpenter must use sufficient force to overcome the spring force and move the guide plate 411 to the advancing posture.

[0196] By moving the guide plate 411 into the advanced position along line S, the carpenter registers or laterally aligns the tab 445 with the notch 447 in the notch 441. In addition, the first recess 437 in the guide plate 411 is registered opposite the first edge 13 proximal to the second edge 14, the second recess 438 is registered opposite the first edge 13 between the notches 441, and the third recess 439 is registered opposite the first edge 13 proximal to the first corner 16. When so registered, the guide plate 411 is able to pivot relative to the body 11 along the arc-shaped arrow line P, as shown. Fig. 12B and 12F4. When the guide plate 411 is pivoted, the tab 445 enters and pivots through the notch 447, which extends far enough into the body 11 so that the tab 445 can completely pivot through the notch 447 without interference. In addition, the first edge 13 of the body 11 of the square 410 enters, moves, and pivots through the first, second, and third recesses 437, 438, and 439, which each extend far enough into the body 430 of the guide plate 411 so that the first edge 13 can completely pivot through the recesses without interference. In the advanced posture of the guide plate 411, the registration and correspondence of the tab 445 and the notch 447 enable the guide plate 411 to pivot among the first, second, and third positions.

[0197] Once the guide plate 411 moves to Fig. 12B and 12F The position shown in (first position, forward posture), the carpenter can follow Fig. 12C The guide plate 411 is slid backward along the arrow line S' in the figure, and the arrow line S' is opposite to the arrow line S. This moves the guide plate 411 into the first position (neutral posture), as shown in FIG. Fig.12D and 12G . In the first position, the tab 445 and its inner edge 452 move out of registration with the notch 447. The inner edge 434 of the guide plate 411 is placed in flat, abutting, facing but slidable contact with the second face 421 of the body 11 of the square 410. The guide plate 411 is now locked against the second face 421 in the first position and cannot be pivoted.

[0198] The carpenter may also move the guide plate 411 into the second position in a similar manner, but by pivoting the guide plate 411 in a pivot direction opposite to the line P instead.

[0199] As the guide plate 411 moves among the first, second and third positions, the inner edge 452 of the tab 445 moves in and out of registration with the notch 447 and out of contact with the first and second faces 420 and 421 of the body 11 of the square 410 .

[0200] When the guide plate 411 is in the first position and the neutral posture, the inner edge 434 of the guide plate 411 is flat, facing, abutting, but in slidable contact with the second surface 421 of the body 11 of the square 410. The inner surface 446 of the notch 441 faces the second surface 436 of the tab 445. The inner edge 434 of the guide plate 411 and the second surface 421 of the body 11 of the square 410 face each other. When the guide plate 411 is in its first position and the neutral posture, the guide plate 411 cannot move out of the first position; when it is in the advanced posture, the guide plate 411 can move out of the first position.

[0201] When the guide plate 411 is in the second position and the neutral posture, the inner edge 434 of the guide plate 411 is in flat, abutting but slidable contact with the first face 420 of the body 11 of the square 410. The inner face 446 of the notch 441 faces the first face 435 of the tab 445. The inner edge 434 of the guide plate 411 and the first face 420 of the body 11 of the square 410 face each other. When the guide plate 411 is in its neutral posture, the guide plate 411 cannot move out of the second position; when it is in the advanced posture, the guide plate 411 can move out of the second position.

[0202] When the guide plate 411 is in the third position and the neutral posture, the inner edge 434 of the guide plate 411 is in flat, abutting but slidable contact with the first edge 13 of the body 11 of the square 410. The inner face 446 of the notch 441 faces the inner edge 452 of the tab 445. The inner edge 434 of the guide plate 411 and the first edge 13 of the body 11 of the square 410 face each other. When the guide plate 411 is in its neutral posture, the guide plate 411 cannot move out of the third position; when it is in the advanced posture, the guide plate 411 can move out of the third position.

[0203] When the guide plate 411 is in each of the first, second and third positions, if the carpenter attempts to pivot the guide plate 411 to another position, the flat inner edge 434 of the guide plate 411 in contact with the flat surface of the body 11 prevents the guide plate 411 from pivoting. Therefore, the guide plate 411 cannot move unless the tab 445 is first moved out of the neutral posture and aligned with the notch 447. Thus, in this embodiment, the first, second and third positions of the guide plate 411 are defined, discrete and indexed positions. In this embodiment, the guide plate 411 can only be placed and temporarily locked into one of these three indexed positions. Other embodiments have fewer or more positions (indexed or otherwise). The guide plate 411 is temporarily locked because it is effectively prevented from being accidentally or accidentally moved out of position, but the carpenter can easily and purposefully move the guide plate 411 out of the position by sliding the guide plate 411 upward into the forward posture. Thus, the structural elements and features described above define an engagement assembly for locking and releasing the guide plate 411 relative to the body 11 of the square 410 .

[0204] Return to reference Fig.11A , the angle ruler 410 also includes similar Figure 4 The example embodiment of the angle ruler 110 depicts a bubble level 140 .

[0205] Figures 13A to 15C Example

[0206] Figures 13A to 14EAn alternative embodiment of a square 410' is shown having additional features. Square 410' is identical in almost all respects to square 410, and therefore, this description uses the same reference numerals for structural elements and features common to both embodiments. In addition, a complete depiction and detailed description of those common structural elements and features are not presented here because such a description is redundant and unnecessary, and the reader already understands the relevant structure of square 410' from the above description of square 410 and its corresponding figures. Square 410' includes a spring pawl 460 that snaps into a detent 465 to help lock guide plate 411 in place.

[0207] Steering Fig. 13B 4, the spring detent 460 is a small, flat, thin finger 461 extending forwardly from the tab 445 parallel to the inner edge 434. The finger 461 has an inner face 463 that abuts the inner edge 434 and forms part of the inner edge 434. The finger 461 terminates in a head 462 that points toward the body 11 of the square 410'. The finger 461 is separated from the guide plate by a thin gap 464 that extends along the length of the finger 461. The finger 461 is resilient, springy, and is able to deform into the gap 464 and return to the guide plate. Fig. 13B The location and layout shown in the.

[0208] The spring pawl 460 engages with a detent 465, which is a slot or notch extending from the first edge 13 of the square 410' into the body 11 of the square 410'. The detent 465 has a width corresponding in size to the width of the head 462 of the finger 461. Thus, the head 462 snaps into the detent 465 and fits within the detent 465, as shown in FIG. Fig. 13C As shown in .

[0209] As the guide plate 411 moves along the body 11 of the square 410' along the lines S and S' as described above, the spring pawl 460 pops in and out of the catch 465. When the pawl 460 is in the catch 465, it applies a friction force that serves to prevent unintentional movement of the guide plate 411; sufficient force must be applied to the guide plate 411 to move the guide plate 411 along the line S. Once that force has been applied and the guide plate 411 is moved, the spring pawl 460 pops out of the catch 465, and the guide plate 411 can slide along the line S. This movement is Figures 14A to 14E Displayed in.

[0210] exist Fig.14A 4, the guide plate 411 is in the third position (neutral posture). The tab 445 is received in the notch 441, and the guide plate 411 cannot move out of the third position. To further ensure that the guide plate 411 will not move accidentally, the spring pawl 460 is engaged with the catch 465. The guide plate 411 will not move out of the neutral posture unless the user applies sufficient force to bias the spring pawl 460 out of engagement with the catch 465.

[0211] exist Fig. 14B (and zoom Fig.14D ), the user has done so. Fig. 14B By applying force to the line S in the middle, the user overcomes the spring force that engages the head 462 in the catch 465. The spring pawl 460 is pushed back into the gap 464. The head 462 pops out of the catch 465 and begins to slide along the first edge 13. This movement continues until Fig. 14C (and zoom Fig.14E ).

[0212] exist Fig.14E (and Fig. 14C ), the head 462 is about to enter the notch 447 of the notch 441. Once entered, the head 462 will leave the first edge 13, and the guide plate 411 can be pivoted to move it into its first or second position.

[0213] Figures 15A to 15C A carpenter's square 480 (hereinafter "square 480") is described. Square 480 has similarities to the above-described embodiments (including square 10). Thus, many of the above-described reference numerals may be used herein to identify the same or similar structural elements or features. For example, square 480 includes a body 11 having three edges. Square 480 has: 1) a bevel edge 12 opposite a right angle 15; 2) a first short edge 13 extending between right angle 15 and a first corner 16, the first corner 16 being formed by and between the first short edge 13 and bevel edge 12; and 3) a second short edge 14 extending between right angle 15 and a second corner 17, the second corner 17 being formed by and between the second short edge 14 and bevel edge 12. These three edges cooperate to define a perimeter edge 18 of body 11 of square 480 itself. Not all structural elements and features of square 480 are described, as the reader is already familiar with those structural elements and features from the remainder of this description.

[0214] The guide plate 19 is pivotally connected to the first edge 13. The guide plate 19 is a generally rectangular piece of material coextensive with the first edge 13. The guide plate 19 is preferably pivotally connected between three indexed positions similar to the indexed positions of the guide plate 19: a first position in which the guide plate 19 is orthogonal to the body 11 in a first direction; a second position in which the guide plate 19 is orthogonal to the body 11 in a second direction opposite to the first direction; and a third position in which the guide plate 19 is coplanar with the body 11. This embodiment of the carpenter's square 480 can also be modified to incorporate a guide plate similar to the guide plate 411 in the square 410 or similar to guide plates in other embodiments of the carpenter's square.

[0215] The body 11 has a first face 482 and an opposing second face 483. The faces 482 and 483 are flat and parallel to each other, separated by the width of the body 11. The faces 482 and 483 are marked with a plurality of indications and measurements. In addition, a slot and a slit are formed completely through the body 11 from the first face 482 to the second face 483. As shown in the previous embodiments, the slots and slits can have various arrangements and embodiments, and the slots and slits of those other embodiments are incorporated herein and should be considered to include variations of the embodiments of the square 480 shown herein.

[0216] For example, the square 480 includes first and second slits 484 and 485. The first slit 484 is parallel to and inside the first edge 13. The first slit 484 has a first end 490 inside the second edge 14 and an opposite second end 491 inside the beveled slot 486. In other embodiments, the first slit 484 has other shapes, orientations, and arrangements, and Figures 15A to 15C The embodiment shown in is not limiting. The second slit 485 is parallel to and inside the second edge 14. The second slit 485 has a first end 492 inside the first edge 13 and an opposite second end 493 inside the beveled slot 486. In other embodiments, the second slit 485 has other shapes, orientations, and arrangements, and Figures 15A to 15C The embodiment shown in is not limiting. Both the first and second slits 484 and 485 are useful together with the jig block 81 to design a cutting pattern, such as Fig. 15B and 15C As shown in .

[0217] Fig. 15B and 15C Jig block 81 is shown applied to first and second slits 484 and 485, respectively. Jig block 81 converts square 480 into a jig that is quickly and easily designed for marking line patterns for cuts along the edge of a workpiece, such as for patterned cuts of stair stringers from 2×12 lumber pieces.

[0218] The jig block 81 is a thin sheet of material, preferably made of the same material as the body 11 of the square 480. The jig block 81 has a long edge 100. The long edge 100 is straight and is not interrupted by notches, protrusions, indentations or other discontinuities. The embodiment of the jig block 81 shown in these figures has four other edges arranged to form an irregular pentagonal shape roughly similar to a baseball home plate. Other shapes are also suitable, as long as the jig block 81 preferably has a long edge 100.

[0219] In use, the jig block 81 is picked up by hand and placed against one of the first and second faces 20 and 21. Fig. 15B480. In the example only, the jig block 81 is placed against the first face 20. The jig block 81 is oriented so that its long edge 100 is generally pointing at the right angle 15 and its through hole 101 is aligned with the second slit 485. The carpenter takes the fixing screw 103 and passes it through the through hole 101 and the second slit 485. In some embodiments, the fixing screw 103 can be screwed directly into the second slit 485, but more preferably, a nut is placed over the free end of the fixing screw 103 and tightened thereon, thereby binding the jig block 81 against the body 11 of the square 480.

[0220] Once the jig block 81 is attached to the face 20 of the square 480, the square 10 is picked up by hand, turned upside down and placed over a workpiece (e.g., a piece of wood). The workpiece has an outer edge to be cut. In order to place the entire face 20 of the square 480 on top of the workpiece 108, the carpenter must move the guide plate 19 to its third position flat and coplanar with respect to the body 11 of the square 480.

[0221] The carpenter manipulates the square 480 so that the long edge 100 of the jig block 81 directly and continuously contacts the outer edge of the workpiece and is placed. This causes the right angle 15 and most of the body 11 of the square 480 to become placed above the workpiece.

[0222] Next, the carpenter adjusts the jig block 81 to ensure that the angle square 480 marks the desired pattern. The carpenter will cut the predetermined pattern, and applying the jig block 81 to the second slit 485 enables the carpenter to cut that pattern. With the long edge 100 of the jig block 81 against the workpiece, the carpenter slightly loosens the set screw 103 so that the angle square 480 can move relative to the jig block 81. The carpenter moves the angle square 480 to achieve the desired ladder height and ladder width. This may require sliding the angle square 480 so that the jig block 81 moves up or down along the second slit 485. It may also be necessary to rotate the body 11 of the angle square 480 while the jig block 81 remains against the outer edge of the wood piece.

[0223] When the carpenter has aligned the square 480 on the workpiece so that the outer edges intersect the desired step height and step width measurements, he tightens the set screw 103. With the square 480 properly dialed, the carpenter can now quickly design the cut line by marking the bird's mouth cut, translating the square 480 to make subsequent bird's mouth cuts, and repeating that process. He continues to translate the square 10 and mark consecutive lines, thereby quickly designing the desired cutting pattern.

[0224] Fig. 15C The same square according to the above description is shown, but the jig block 81 is applied to the first slit 484 instead of the second slit 485. The reader will understand that the above description also applies where the first slit 484 replaces the second slit 485.

[0225] The above describes the preferred embodiments comprehensively and clearly so that those skilled in the art can understand, make and use the embodiments. Those skilled in the art will recognize that the above description may be modified without departing from the spirit of the present specification, and some embodiments include only those described elements and features or a subset thereof. To the extent that the modifications do not depart from the spirit of the present specification, it is intended that the modifications are included within the scope of the present specification.

Claims

1. A carpenter's square, comprising: a body comprising a first edge, a second edge, and a third edge; a guide plate pivotally connected to the first edge for movement relative to the body among first, second and third positions; In the first position, the guide plate is orthogonal to the body in a first direction; In the second position, the guide plate is orthogonal to the body in a second direction opposite to the first direction; and In the third position, the guide plate is coplanar with the body; wherein a hinge assembly pivotally connects the guide plate to the first edge and comprises: a notch in the body, a recess in the notch, and a pin mounted in the notch; a tab protruding from the guide plate and mounted on the pin for reciprocating and rocking movement on the pin; and The tab moves between a neutral position and an advanced position, in which the tab is misaligned with the notch in the notch and the guide plate cannot move among the first, second and third positions, and in which the tab is aligned with the notch in the notch and the guide plate can move among the first, second and third positions. 2 . The carpenter's square of claim 1 , wherein the notch extends from the first edge into the body of the carpenter's square, and the recess further extends from the notch into the body.

3. The carpenter's square of claim 1, wherein the tab reciprocates between the neutral position and the advanced position.

4. The carpenter's square according to claim 1, wherein: The guide plate includes a recessed portion; In the advanced position, the recess is registered with the first edge so that the first edge can move through the recess as the guide plate moves among the first, second, and third positions; and In the neutral position, the recess is offset from the first edge such that the first edge cannot move through the recess when the guide plate moves among the first, second, and third positions.

5. The carpenter's square according to claim 1, wherein: The notch includes a notch surface, and the tab includes first, second and third surfaces; When the guide plate is in the first position and the tab is in the neutral posture, the notch surface of the notch and the first surface of the tab face each other; When the guide plate is in the second position and the tab is in the neutral posture, the notch surface of the notch and the second surface of the tab face each other; and When the guide plate is in the third position and the tab is in the neutral posture, the notch surface of the notch and the third surface of the tab face each other.

6. The carpenter's square of claim 5, wherein the notched surface, the first surface, the second surface, and the third surface are all flat.

7. The carpenter's square according to claim 1, wherein: The guide plate includes an inner edge, and the body of the carpenter's square includes a first face, a second face, and the first edge; When the guide plate is in the first position and the tab is in the neutral posture, the inner edge of the guide plate and the second surface of the body face each other; When the guide plate is in the second position and the tab is in the neutral position, the inner edge of the guide plate and the first surface of the body face each other; and When the guide plate is in the third position and the tab is in the neutral posture, the inner edge of the guide plate and the first edge of the body face each other.

8. The carpenter's square of claim 7, wherein the inner edge, the first face, the second face, and the first edge are all flat.

9. A carpenter's square, comprising: a body comprising a first edge, a second edge, and a third edge; a guide plate pivotally connected to the first edge for movement relative to the body among first, second and third positions; In the first position, the guide plate is orthogonal to the body in a first direction; In the second position, the guide plate is orthogonal to the body in a second direction opposite to the first direction; and In the third position, the guide plate is coplanar with the body; wherein a hinge assembly pivotally connects the guide plate to the first edge and comprises: a notch in the body and a pin mounted in the notch; a tab protruding from the guide plate and mounted on the pin for reciprocating and rocking movement on the pin in the notch; and The tab moves between a neutral position in which the tab prevents the guide plate from moving among the first, second, and third positions and an advanced position in which the tab enables the guide plate to move among the first, second, and third positions.

10. The carpenter's square of claim 9, wherein the tab reciprocates between the neutral position and the advanced position.

11. The carpenter's square according to claim 9, wherein: The guide plate includes a recessed portion; In the advanced position, the recess is registered with the first edge so that the first edge can move through the recess as the guide plate moves among the first, second, and third positions; and In the neutral position, the recess is offset from the first edge such that the first edge cannot move through the recess when the guide plate moves among the first, second, and third positions.

12. The carpenter's square according to claim 9, wherein: The notch includes a notch surface, and the tab includes first, second and third surfaces; When the guide plate is in the first position and the tab is in the neutral posture, the notch surface of the notch and the first surface of the tab face each other; When the guide plate is in the second position and the tab is in the neutral posture, the notch surface of the notch and the second surface of the tab face each other; and When the guide plate is in the third position and the tab is in the neutral posture, the notch surface of the notch and the third surface of the tab face each other.

13. The carpenter's square of claim 12, wherein the notched surface, the first surface, the second surface, and the third surface are all flat.

14. The carpenter's square according to claim 9, wherein: The guide plate includes an inner edge, and the body of the carpenter's square includes a first face, a second face, and the first edge; When the guide plate is in the first position and the tab is in the neutral posture, the inner edge of the guide plate and the second surface of the body face each other; When the guide plate is in the second position and the tab is in the neutral position, the inner edge of the guide plate and the first surface of the body face each other; and When the guide plate is in the third position and the tab is in the neutral posture, the inner edge of the guide plate and the first edge of the body face each other.

15. The carpenter's square of claim 14, wherein the inner edge, the first face, the second face, and the first edge are all flat.

16. A carpenter's square, comprising: a body comprising a first edge, a second edge, and a third edge; a guide plate pivotally connected to the first edge for movement relative to the body among first, second and third positions; In the first position, the guide plate is orthogonal to the body in a first direction; In the second position, the guide plate is orthogonal to the body in a second direction opposite to the first direction; and In the third position, the guide plate is coplanar with the body; wherein a hinge assembly pivotally connects the guide plate to the first edge and comprises: a notch in the body, a recess in the notch, and a pin mounted in the notch; a tab protruding from the guide plate and mounted on the pin for reciprocating and rocking movement on the pin in the notch; and The tab moves between a neutral position and an advanced position, in which the tab is misaligned with the recess and the guide plate cannot move among the first, second and third positions, and in which the tab is aligned with the recess and the guide plate can move among the first, second and third positions.

17. The carpenter's square of claim 16, wherein the notch extends from the first edge into the body of the carpenter's square, and the recess extends further from the notch into the body.

18. The carpenter's square of claim 16, wherein the tab reciprocates between the neutral position and the advanced position.

19. The carpenter's square of claim 16, wherein: The guide plate includes a recessed portion; In the advanced position, the recess is registered with the first edge so that the first edge can move through the recess as the guide plate moves among the first, second, and third positions; and In the neutral position, the recess is offset from the first edge such that the first edge cannot move through the recess when the guide plate moves among the first, second, and third positions.

20. The carpenter's square of claim 16, wherein: The notch includes a notch surface, and the tab includes first, second and third surfaces; When the guide plate is in the first position and the tab is in the neutral posture, the notch surface of the notch and the first surface of the tab face each other; When the guide plate is in the second position and the tab is in the neutral posture, the notch surface of the notch and the second surface of the tab face each other; and When the guide plate is in the third position and the tab is in the neutral posture, the notch surface of the notch and the third surface of the tab face each other.

21. The carpenter's square of claim 20, wherein the notched surface, the first surface, the second surface, and the third surface are all flat.

22. The carpenter's square of claim 16, wherein: The guide plate includes an inner edge, and the body of the carpenter's square includes a first face, a second face, and the first edge; When the guide plate is in the first position and the tab is in the neutral posture, the inner edge of the guide plate and the second surface of the body face each other; When the guide plate is in the second position and the tab is in the neutral position, the inner edge of the guide plate and the first surface of the body face each other; and When the guide plate is in the third position and the tab is in the neutral posture, the inner edge of the guide plate and the first edge of the body face each other.

23. The carpenter's square of claim 22, wherein the inner edge, the first face, the second face, and the first edge are all flat.

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