Self-adjusting marking tool for rectangular construction panels

Abstract

A self-adjusting marking tool provides a single-step layout of cut lines on a rectangular construction panel based on a selected roof pitch. The tool includes an elongated body having a straight marking edge, a first edge guide configured to bear against a first panel edge, and a second edge guide configured to bear against a second panel edge parallel to the first panel edge. An adjustable positioning mechanism repositions at least one edge guide among a plurality of indexed positions labeled with pitch values, and a locking element secures the selected position. With both edge guides simultaneously bearing against the respective panel edges, the marking edge is constrained to a predetermined angular orientation corresponding to the selected pitch value. A user marks a cut line by drawing along the marking edge without performing trigonometric calculations, consulting rafter tables, or measuring angles.

Description

SELF-ADJUSTING MARKING TOOL FOR RECTANGULAR CONSTRUCTION PANELSBACKGROUND OF THE INVENTION1. Field of the Invention

[0001] The present invention relates generally construction layout and marking tools, and more particularly to an angle-setting marking tool that automatically establishes accurate cutting angles on construction panels based on user-selected roof pitch settings, without requiring separate angle conversion, rafters table reference, multipoint measurement, or independent angle verification.2. Description of Related Art

[0002] In residential and commercial roof construction, sheathing panels (typically 4' x 8' plywood or OSB sheets) must be cut at precise angles where roof planes intersect at hips and valleys. The cutting angle is determined by the roof pitch — expressed as a ratio of vertical rise to the horizontal run (e.g., 6 / 12 means 6 inches of rise per 12 inches of runs). The relationship between roof pitch and the corresponding cutting orientation is defined by geometric principles. In conventional practice, determining the correct cutting line typically requires either reference to conversion tables, indirect geometric layout methods, or multipoint measurement procedures in order to establish the proper angle.

[0003] This conversion process presents significant challenges on the job site. In conventional practice, workers typically rely on indirect layout methods, such as marking multiple reference points along panel edges, consulting pitch-to-angle reference tables, or using separate angle-measuring tools to establish the desired cutting orientation. These approaches introduce opportunities for cumulative errors, consume time, and require additional setup steps before the final cut line can be drawn.

[0004] Limitations of Existing Tools

[0005] Speed Squares and Rafter Squares. The conventional carpenter’s speed square (see, e.g., U.S. Pat. No. 12,145,397, describing a triangular carpenter’s tool with a pivoting fence) provides angle markings along its hypotenuse edge and includes rafter tables stamped on the tool body. However, using these tools for hip and valley cuts requires the worker to: (1) look up the pitch in the rafter table, (2) identify the corresponding angle value, (3) align the tool to that angle marking, and (4) hold the tool steady while marking. This multi-step process introduces cumulative errors at each stage.

[0006] Traditional combination squares (see, e.g., U.S. Pat. No. 12,246,899, describing combination square construction) allow angle adjustment but requires the user to set and verify the angle using a separate protractor or angle gauge. The tool does not inherently “know” what angle corresponds to a given roof pitch.

[0007] Electronic angle measurement devices can measure and display angles with high precision, but they measure existing angles rather than establishing angles based on pitch ratios. The worker must still calculate or look up the target angle, then adjust the panel or saw to match.

[0008] Precision measuring instruments (see, e.g., U.S. Pat. No. 12,313,401, describing a chamfer gauge with interchangeable anvils for measuring angles) are designed for verification rather than layout, and their cost and complexity make them impractical for field use in roofing applications.

[0009] What is needed is a marking tool that directly converts roof pitch selection into the correct cutting angle through the tool’s geometry itself — eliminating the intermediate steps of calculation, table lookup, and angle measurement. The tool should allow a worker who knows only the roof pitch (information readily available from architectural drawings) to mark accurate cutting lines in a single operation.BRIEF SUMMARY OF THE INVENTION

[0010] The following presents a simplified summary of some embodiments of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key / critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some embodiments of the invention in a simplified form as a prelude to the more detailed description that is presented later.

[0011] It is a main object of the present disclosure to provide for a self-adjusting marking tool that mechanically embodies a predetermined geometric relationship between roof pitch ratios and cutting angles, enabling single-step marking of hip and valley cuts on roof sheathing panels.

[0012] In accordance with one aspect of the invention, a marking tool is provided comprising an elongated body having a straight marking edge configured to guide a marking instrument along a desired cut line. The first edge guide is disposed at the first end of the elongated body and is configured to engage the first edge of a rectangular panel. A second edge guide is disposed at the second end of the elongated body and is configured to simultaneously engage a second edge of the panel that is spatially related to the first edge. An adjustable positioning mechanism operatively connects at least one of the edge guides to the elongated body and permits selective repositioning of the edge guide among a plurality of predetermined positions. Each predetermined position corresponds to one or more predefined pitch parameters. A locking element maintains the selected position during marking operations.

[0013] The predetermined positions are established during tool design and manufacture by calculating the geometric relationship between edge guide locations and the resulting angle of the marking edge relative to the panel edges. For each predefined roof pitch parameter, the corresponding edge guide positions are calculated based on the geometric relationship between pitch and cutting orientation. These relationships are then embedded in the physical structure of the adjustment mechanism — as discrete detent positions, graduated scale markings, or indexed stops — so that selecting a pitch setting automatically configures the tool geometry to produce the corresponding cutting angle.

[0014] In operation, a user selects the desired roof pitch on the adjustment mechanism and engages the locking element. The tool is then placed on the sheathing panel with the first edge guide bearing against one panel edge and the second edge guide bearing against a second panel edge having a predetermined geometric relationship with the first panel edge. Because both edge guides are in simultaneous contact with their respective panel edges, the straight marking edge is constrained to a single angular orientation determined entirely by the embedded geometric relationship. The user then draws a line along the marking edge to establish the cut line. The orientation is established without requiring separate angle conversion, multipoint layout, or independent angle verification.

[0015] The invention thus transfers the geometric determination process from the point of use to the point of manufacture, where it can be computed at once with high precision and permanently embedded in the tool structure. This approach eliminates: (a) separate angle conversion and indirect geometric interpretation; (b) interpretation of rafter tables; (c) multi-step setup procedures; (d) cumulative measurement error; and (e) the need for mathematical knowledge by the end user.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0016] Other features and advantages of the present invention will become apparent when the following detailed description is read in conjunction with the accompanying drawings, in which:

[0017] FIG. 1A is a perspective view of the self-adjusting marking tool, showing the adjustment knobs unassembled.

[0018] FIG. IB is a perspective view of the self-adjusting marking tool, showing the adjustment knob assembled.

[0019] FIG. 1C is a close-up view of the angled section of the tool.

[0020] FIG. 2A is a top view of a section of the tool showing the adjustment mechanism’s ability to slide.

[0021] FIG. 2B is a side view of the tool showing the adjustment mechanism’s ability to slide.

[0022] FIG. 3A is a top plan view of the tool showing the adjustment mechanism in a given angle position, illustrating the change in edge guide position.

[0023] FIG. 3B is a top plan view of the tool showing the adjustment mechanism in another angle position, illustrating the change in edge guide position.DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0024] The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out the invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein to specifically provide a self-adjusting marking tool for roofing panels, herein roofing panels are synonymous with roof sheathing panels.

[0025] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. The terms “a” or “an,” as used herein, are defined as to mean “at least one.” The term “plurality,” as used herein, is defined as two or more. The term “another,” as used herein, is defined as at least a second or more. The terms “including” and / or “having,” as used herein, are defined as comprising (i.e., open language). The term “providing” is defined herein in its broadest sense, e.g., bringing / coming into physical existence, making available, and / or supplying to someone or something, in whole or in multiple parts at once or over a period of time. As used herein, the terms “about,” “generally,” or “approximately” apply to all numeric values whether or not explicitly indicated. These terms generally refer to a range of numbers that one of skill in the art would consider near the stated amount by about 0%, 5%, or 10%, including increments therein. In many instances these terms may include numbers that are rounded to the nearest significant figure.

[0026] According to a first embodiment, there is provided a self-adjusting marking tool 10 comprising an elongated body 12 having a first end 14 and a second end 16. The elongated body 12 includes a straight marking edge 18 extending between the first and second ends 14, 16. The marking edge 18 is configured to guide a marking instrument (such as a pencil, scribe, or chalk line) to produce a straight line on a workpiece.

[0027] Although the present embodiment is described with reference to roof sheathing panels, the marking tool is equally applicable to other rectangular construction panels where angled cuts corresponding to pitch values are required. Such panels may include, without limitation, gypsum board for cathedral ceilings, oriented strand board (OSB), plywood, medium-density fiberboard (MDF), cement board, or other rectangular sheet materials used in construction applications.

[0028] In one embodiment, a first-edge guide 20 is disposed at or near the first end 14 of the elongated body 12. In one embodiment, the first edge guide 20 extends transversely from the elongated body 12 and is adjustably mounted thereto. In one embodiment, a second edge guide 30 is disposed at or near the second end 16 of the elongated body 12.

[0029] Adjustable Positioning Mechanism

[0030] In one embodiment, an adjustable positioning mechanism 40 operatively connects the first edge guide 20 to the elongated body 12. In one embodiment, the adjustable positioning mechanism 40 comprises a slide track 42 formed in or attached to the elongated body 12, and a slide member 44 that is received in the slide track 42 for linear movement there along. The first edge guide 20 is attached to the slide member 44 so that movement of the slide member 44 along the slide track 42 repositions the first edge guide 20 relative to the elongated body 12. In one embodiment, the slide member 44 includes or is coupled to an adjustment knob configured to be grasped by a user to translate the slide member along the slide track.

[0031] The slide track 42 includes a plurality of indexed positions 46a, 46b, 46c, etc., corresponding to standard roof pitches. In one embodiment, indexed positions may be provided for a range of predefined roof pitch values. Each indexed position is labeled with its corresponding pitch value for easy identification. In one embodiment, the slide track includes indicia adjacent to the indexed positions, the indicia comprising printed, etched, engraved, stamped, molded, or laser-marked pitch values.

[0032] A locking element 50 is provided to secure the slide member 44 at a selected indexed position. In the illustrated embodiment, the locking element 50 comprises a spring-loaded detent that engages a corresponding detent recess at each indexed position. Alternative locking arrangements may include thumbscrews, cam locks, toggle clamps, or friction locks.

[0033] Geometric Relationships

[0034] The indexed positions 46 are established during tool design and manufacture according to geometric principles. For a rectangular panel P having a first edge El of length LI and a second edge E2 of length L2 (where El and E2 have a predetermined geometric relationship), placing the tool 10 on the panel with the first edge guide 20 in contact with El at a first point and the second edge guide 30 in contact with E2 at a second point establishes a line (the marking edge 18) that makes an angle 9 with the first edge El.

[0035] The resulting angular orientation of the marking edge is determined by the relative spatial positions of the first and second edge guides. These positions are established during tool design to correspond to predefined roof pitch parameters based on the geometric relationship between pitch and cutting orientation.

[0036] By calculating the required edge guide positions for each predefined pitch parameter and manufacturing the indexed positions 46 at these calculated locations, the tool 10 automatically produce the correct cutting angle when a pitch setting is selected.

[0037] Method of Use

[0038] In use, the worker first determines the roof pitch from the construction drawings or by measurement. The worker then adjusts the positioning mechanism 40 to the indexed position 46 corresponding to that pitch and engages the locking element 50.

[0039] The worker places the panel P on a work surface and positions the tool 10 on the panel with the first edge guide 20 bearing against the first panel edge El and the second edge guide 30 bearing against the second panel edge E2 having a predetermined geometric relationship with the first panel edge. With both edge guides in simultaneous contact with their respective edges, the marking edge 18 is constrained to the correct angular orientation. In one embodiment, the first edge guide 20 comprises a generally cylindrical peg, pin, or post projecting from the elongated body 12 and configured to contact and register against the first panel edge El.

[0040] In one embodiment, the second edge guide 30 comprises a generally cylindrical peg, pin, or post projecting from the elongated body 12 and configured to contact and register against the second panel edge E2. Each cylindrical peg defines an edge-stop contact surface such that, when the tool is placed on the panel P, the peg contacts the panel edge along a tangent line or point contact sufficient to prevent further motion of the tool in a direction normal to the contacted edge, thereby constraining the position of the elongated body 12 relative to the panel edges.

[0041] The worker then draws a line along the marking edge 18 using any suitable marking instrument. This line represents the cutting line for a hip or valley cut at the selected roof pitch.

[0042] The tool 10 may be repositioned along the panel edges to mark multiple parallel cuts or cuts at different locations without changing the pitch setting. When a different pitch is required, the worker simply releases the locking element 50, moves the slide member 44 to the new indexed position, and re-engages the locking element 50.

[0043] Alternative Embodiments

[0044] While the previous embodiment employs a linear slide track for the adjustable positioning mechanism, other mechanisms may be used. For example, the second edge guide may be mounted on a pivoting arm that rotates about a fixed axis, with indexed angular positions corresponding to different pitches. Alternatively, both edge guides may be adjustable, with coordinated movement governed by a linkage, cam, or gear mechanism.

[0045] The tool may be fabricated from various materials including aluminum, steel, high-strength plastic, or fiber-reinforced composite. The marking edge may be provided with a groove or channel to guide a marking instrument, or with an upstanding lip to serve as a saw guide for direct cutting.

[0046] Additional features may include: a bubble level for verifying horizontal orientation; a ruler or scale along the marking edge for measuring cut length; interchangeable edge guides for different panel thicknesses; a hanging hole for storage; and protective end caps.

Claims

CLAIMSWhat is claimed is:

1. A marking tool for laying out an angled cut line on a rectangular construction panel having two spaced first and second edges, the marking tool comprising: a n elongated body extending between a first end and a second end, the elongated body including a straight marking edge configured to guide a marking instrument; a first edge-engaging member coupled to the elongated body and configured to register the marking tool against the first edge of the construction panel; a second edge-engaging member coupled to the elongated body and configured to register the marking tool against the second edge of the construction panel while the first edge-engaging member registers against the first edge, the second edge being spaced from the first edge; and a n angle-setting adjustment assembly coupled to the elongated body and operatively associated with at least one of the first edge-engaging member or the second edge-engaging member, the angle-setting adjustment assembly being configurable to a selected one of a plurality of discrete pitch settings, wherein configuring the angle-setting adjustment assembly to the selected discrete pitch setting causes the straight marking edge, when the first and second edgeengaging members simultaneously register against the first and second edges, to assume a predetermined angular orientation relative to at least one of the first edge or the second edge corresponding to the selected discrete pitch setting.

2. The marking tool of claim 1, wherein the plurality of discrete pitch settings includes a plurality of roof pitch ratios including values between approximately 1 / 12 and 18 / 12.

3. The marking tool of claim 1, further comprising a locking element configured to retain the angle-setting adjustment assembly at the selected discrete pitch setting during marking.

4. The marking tool of claim 1, wherein at least one of the first edge-engaging member or the second edge-engaging member comprises a generally cylindrical peg configured to contact a corresponding panel edge.

5. The marking tool of claim 1, wherein at least one of the first edge-engaging member or the second edge-engaging member comprises a fence portion extending transversely relative to the elongated body and configured to bear against a corresponding panel edge.

6. The marking tool of claim 1, wherein the angle-setting adjustment assembly comprises at least one of: a sliding member movable along a guide, a pivoting arm movable about a pivot axis, a cam mechanism, a linkage, or a gear-driven mechanism.

7. The marking tool of claim 1, wherein the angle-setting adjustment assembly includes indicia identifying the plurality of discrete pitch settings.

8. The marking tool of claim 1, wherein the straight marking edge includes a groove, channel, or lip configured to guide the marking instrument.

9. The marking tool of claim 1, wherein the predetermined angular orientation is established by a predetermined mapping between roof pitch values and marking angles embedded in the geometry of the marking tool.

10. A self-adjusting marking tool for construction panels, compri sing: an elongated body having a straight marking edge extending between a first end and a second end; a first edge guide disposed at or near the first end, the first edge guide comprising a generally cylindrical peg configured to contact a first edge of a rectangular p anel; a second edge guide disposed at or near the second end, the second edge guide comprising a generally cylindrical peg configured to contact a second edge of the rectangular panel that is spaced from the first edge while the first edge guide contacts the first edge; an adjustable positioning mechanism operatively connecting the first edge guide to the elongated body, the adjustable positioning mechanism compri sing: (i) a slide track extending along the elongated body , and (ii) a slide member received in the slide track for linear movement, the first edge guide being carried by the slide me mber; a plurality of indexed positions along the slide track, each indexed position being labeled with a respective roof pitch value ; and a locking element comprising a spring-loaded detent configured to releasably engage a respective detent recess at each indexed posi tion; wherein, with the slide member locked at a selected indexed position and with the first and second edge guides simultaneously contacting the first and second edges of the panel, the straight marking edge is constrained to a predetermined angular orientation corresponding to the roof pitch value of the selected indexed position.

11. The marking tool of claim 10, wherein the roof pitch values include a plurality of roof pitch ratios including values between approximately 1 / 12 and 18 / 12.

12. The marking tool of claim 10, wherein the straight marking edge includes a groove or channel configured to guide a pencil or scribe.

13. The marking tool of claim 10, wherein the elongated body is fabricated from aluminum, steel, or reinforced polymer.

14. The marking tool of claim 10, wherein the slide track includes printed indicia adjacent the indexed positions corresponding to the roof pitch values.

15. A method of marking an angled cut line on a rectangular construction panel using the marking tool of claim 10, comprising : setting the slide member of the marking tool to an indexed position labeled with a roof pitch value ; engaging a spring -loaded detent to lock the slide member at the indexed position ;placing the marking tool on the panel with first and second cylindrical pegs simultaneously contacting first and second edges of the panel; an dmarking a line along the straight marking edge of the marking tool, wherein the line is at a predetermined angle corresponding to the roof pitch value.

16. The marking tool of claim 1, wherein the rectangular construction panel comprises a roof sheathing panel and the angled cut line corresponds to a hip or valley cut.

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