US2917831A

US2917831A - Adjustable mitering square

Info

Publication number: US2917831A
Application number: US638748A
Authority: US
Inventors: John E Gordon
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-02-07
Filing date: 1957-02-07
Publication date: 1959-12-22
Anticipated expiration: 1976-12-22

Description

J. E. GORDON 2,917,831

ADJUSTABLE MITERING SQUARE Filed Feb. 7, 1957 4 INVENTOR. l Jam f 60/200 United 1 States Patent 2,917,831 ADJUSTABLE MITERING SQUARE John E. Gordon, Seattle, Wash. Application February 7, 1957, Serial No. 638,748

2 Claims. (CI. 33-40) This invention relates to construction tools and more particularly relates to an adjustable mitering tool to facilitate ready and easy marking of building rafters and the like.

An object of my invention is to provide a new and improved tool of simple and inexpensive construction and operation for setting and laying out the angles at which the end of a rafter is to be cut.

Another object of my invention is the provision of a novel hand tool for setting the angles at which a rafter is to be cut and which tool may be quickly and accurately applied to such a rafter board so as to facilitate marking of cut lines thereon.

A further object of my invention is to provide an improved adjustable mitering square for setting the angles at which rafters and the like are cut and which may be quickly and accurately applied to a rafter board for marking the cut lines even though the board may be slightly out of square.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same parts throughout the several views and in which:

Fig. 1 is a perspective view of the mitering tool applied to a rafter board which is shown in dotted lines;

Fig. 2 is an elevation view of the tool positioned so that two of the outer surfaces are visible;

Fig. 3 is a detail transverse section view taken on a plane indicated substantially at 3-3 of Fig. 2;

Fig. 4 is a detail transverse section view taken on a plane as indicated substantially at 4-4 in Fig. 2; and

Fig. 5 is an elevation view showing a rear side of the invention not shown in Fig. 1.

The tool comprising the present invention is primarily adapted for defining and laying out the angles at which the ends of rafter boards and the like are to be cut in relation to the side surfaces of such boards. The mitering tool includes an elongated body member which has a generally rectangular cross section and which may be constructed of any suitable rigid material such as wood, molded plastic or the like. The body member 10 is provided with at least a pair of outer surfaces 11 and 12 which lie in planes that are perpendicular to each other. Surface 11 provides a planar surface bearing which is to be laid against one of the side surfaces of the rafter board B shown in dotted lines in Fig. 1. The forward portion of surface 12 defines a linear marking edge 13 which lies substantially in the plane of the surface bearing 11. The body member.10 has an elongated slot 14 therein extending along the marking edge 13. The slot 14 is disposed at a forty-five degree angle with respect to each of the surfaces 11 and 12 and, as best seen in Fig. 2, the slot 14 opens through the rear portion of the body member 10 at 15 and 16.

[Asupporting member or projecting portion 17 is atfixed. Ion the upper ;portion of the boar m m e and projects outwardly from the bearing surface 11. 'The supporting member 17 has a downwardly facing Edge 20 intersects the surface 18 at a point which may arbitrarily be termed a hook point which comprises the center of swinging movement of the surface 11 and the body member 10 when the body member is supported by the edge 20 on a rafter board. It will be noted that edge 20 lies in. two planes which are perpendicular to surface 11, one plane being parallel to marking edge 13 and the other plane being perpendicular to the marking edge 13.

An adjustable blade 21 is swingablymounted in the groove 14 and has an inner linear edge 22 which is contiguous to the marking edge 13 of the body member to define miter cut angles therebetween. A pivot 23 is secured on the body member at the rear end portion of the groove 14 and in the opening 16 thereof. The blade 21 has an inner end portion 24 which is notched at 25 to receive the pivot 23 therein. An arcuate guideway or groove 26 is formed in one of the walls of slot 14 and is generally circular in shapeabout the pivot 23. A guiding element or pin 27 is affixed to the inner end portion of plate 21 and is carried in the groove 26 to be guided thereby 23. j j

Pivot 23 defines the point about which plate 21 swings and pivot 23 is disposed in a plane which is perpendicular to the surface 11 and parallel to marking edge13) and which plane includes the supporting edge 20 and the hook point defined thereby.

The blade 21 is swingable from the position shown in Fig. 2, wherein the edge22 is perpendicular to the marking edge 13, to positions where the

edges

22 and 13 define acuteangles and is further swingable inwardly. into slot 14 which substantially completely houses blade; 21 and thereby permits the tool to fold into small corn pass. When the edge 22 is disposed normal to the marking edge 13, the edge 22 and surface 18 and supporting edge 20 lie in a common plane which is per pendicular to surface 11 and marking edge 13.

A stop 28 is formed in the body member 10 at the upper end thereof for engaging an abutting surface 29 of blade 21 to restrict upward swinging movement there- I of beyond the position of blade 21 wherein

edges

22 and 13 are perpendicular to each other.

A thumb-receiving recess 30 is provided in surface 11 adjacent slot 14 to facilitate ready and easy gripping of blade 21.

A pair of

elongated scale members

31 and 32 are mounted on the surface 33 of body member 10. The

elongated scale members

31 and 32 have

scales

31a and 32a thereon which may be marked off in any suit- Member 31 is affixed to the body member 10 as by screws 34. Member 32 Y is. swingably mounted on pivot screw 35 which is se cured to the body member 10 and which extends through I a suitably provided aperture in the scale member 32. Scale member 32 is provided with a circular head portion 36 around the pivot screw 35 and a scale 37 marked L off in degrees is provided around the periphery thereof to, facilitate determining the angle between swingable blade 32 and fixed blade 31 orthe edge of surface 331.2 of body member 10. Scale, member 32 may be swung:

able dimensions such as inches.

2,917,831 Patented Dec. 22, was

as the plate is swung about pivot 3 into end-to-end relation and linear alignment with scale member 31 as shown in the dotted position C in Fig. 5 to facilitate measuring along the scales 32a and 31m.

Means are provided for presettingthe position of blade 21, dependent upon the slope of the roof for which the rafters to be cut are to be used. In the form shown such means include scales 38 and 39 onthe surfaces 11 and 12' respectively and along theedges of slot 14. One of the scales such as scale 38 may be marked for the angle at which blade 21 is to be set for the marking of jack and common rafters. The other scale such as. 39 may be graduated for the positions of blade 21 in the marking of hip rafters. 1

In the operation of the tool, the position ofthe blade will. be. set in accordance with the graduations of the sc 'a'le dependent upon the type of. rafters to be cut. For instance, if common rafters are tobe cut, the blade will be positioned in accordance withscale 38. When the blade 21 is set in its desired position, thebody member is placed against the side surface of-the rafter board with the surface bearing 11 engaging the rafter board. The supporting edge 20 will be hooked over the corner of the rafter board and will engage the adjacent surface. The body member 10 will then be swung about the axis defined by the sup'portingedge 20 until blade 21 engages the top surface of the rafter board. Provided that the adjacent surfaces of the rafter board are substantially perpendicular to each other, the marking edge 13 on the body member 10 and the edge 21 of blade 21 will both engage the respective surfaces of the rafter board along their entire lengths to facilitate ready and easy marking of the rafter board. When the described operation is used, it is substantially impossible to inaccurately place the blade edge 22 and marking edge 13 on the rafter board so as to define improper angles. When the blade edge 22 and the marking edge 13 engage the rafter board, these edges may be moved along the rafter board slightly to facilitate positioning of the angle cut lines at the proper position along the length of the board. If common rafters are to be cut a mark may be made only along the. marking edge 13 because the end surfaces of common rafters are generally disposed at right angles with the side surfaces of the rafter board and are generally disposed at acute angles with the top surfaces of the rafter boards.

If jack rafters are to be cut, the rafter board will also be" -marked alongthe blade-edge 22 to facilitate cutting of the jack rafters at angles with both the top and side surfaces thereof.

In cutting hip rafters, the position of the blade will be' determined in accordance with the scale 39 which is graduated for hip rafters and the rafter board will be marked along both of the

edges

13 and 22.

The tool comprising the present inventionis also readily adapted for marking the rafter board for cutting of the wall seat therein where the rafter rests upon the upright wall of a building. It should be remembered that normally, a triangular section must be cut out of the bottom surface of the rafter board to form this wall seat and the section cut out will be shaped as a right triangle. One of the legs of this triangle willbe substantially vertical and this leg of the triangle will be marked on the rafter board by sliding the tool along the board as shown in position 1 and then marking the line along the marking edge 13. The other leg of the triangle which is to be cut, will be disposed substantially horizontally to rest upon the top of the building wall. This horizontal leg of the triangle is marked by laying the bearing surface 11 of the body member 10 againstthe bottom surface of the rafter board and the supporting edge Ztland the blade edge-22 will engage the upright sidesurfaceof the rafter board whichwas previously engaged'by the'body member? bearing surface 11. Th'e tw'o sides of the triangle Section. to becut' will. then be properly oriented with Pect.tct each-other-anct-withthe bottomisuriate of th rafter board B and the depth of the recess formed by the triangular cut need only be measured before the horizontal leg of the triangle is marked.

in performing this operation of marking the rafter board, the adjustment of the blade 21 remains unchanged after having marked the upper end of the rafter board which engages the ridge board of the building construction. In properly positioning the body member and blade on the rafter board for making these marks for the wall seat the utilization of the supporting edge 20 in properly positioning the marking edges 13 and 22 is as important as in making the marks for the miter cut at the upper end of the rafter board. The bearing surface 11 of the tool is again applied toone of the rafter board surfaces and the supporting edge 20 is hooked over the rafter board and the body member and bearing surface 11 will then be swung about edge 20 until the blade edge 22 engages the rafter board.

it will be seen that I have provided a new and improved tool for quickly and accurately setting and laying out miter cuts which are to be made in a rafter board or the like and when the tool is used in the method specified, the marking edges of the body member and blade will engage the rafter board along their respective entire lengths. f

it should also be apparent that I have provided a novel tool of simple and inexpensive construction and operation which is particularly well adapted for marking the miter cuts in a rafter board or the like which is slightly out of square by placing the supporting edge of the tool upon one of the acute angledacorners of the rafter board and tnenoperating the tool in the specified manner, the result beiug'that the outer end portion of the blade edge may be slightly elevated from the adjacent surface of the rafter board,.but the setting. of the angle to be cut will be as accurate as is possible.

It will, of course, be understood that various changes may be made in theform, detail, arrangement and proportion of the parts without departing from-the scope of my invention which consists of the matter described herein and set forth in the appended claims.

What is claimed is:

1. In a mitering tool, a body member. having means lying in a plane and defining a surface bearing, said body member having a linear marking edge'intheplane of said bearing, a pivot on said-body member, a.- blade swingably mounted on said pivot for movement. in a plane which intersects the plane of the surface hearing at forty-five degrees along. said linear edge, said blade having an inner linear edge contiguous to said linear marking edge to form different angles therewith, and means on said body member defining a" supporting edge extending outwardly from and normal to said surface bearing and lying in a plane which passes through the pivot and which lies perpendicular to the plane of the surface bearing, whereby said surface bearing may be placed upon a surface ofa rafter board or the like with said supporting edge engaging an adjacent surface of the board and'the body member may then be swung about said edge to engage the board and thereby facilitate marking of the board at the desired angles along' said linear marking edge and inner linear edge.

2. In a tool for laying out miter cut angles on rafter boards and the like comprising a body member having means defining a planar surface bearing for engaging a surface of a rafter board, said surface bearinghavinga forward portion and also having a rearportion, said-body member defining a marking edge in the plane of said bearing, a blade swingably mounted on the upper end portion of the body member and having a linear inner. edge-contiguous to said-marking edge, saidv blade swing ing in aplane Whichintersects the plane ofithe surface' bearing along said marking edge and being adjustab'lef be--' tween positions wherein said edgesare normalto? each other and wherein said edges define a'n acute ang1e;.-

body member having a projection on the upper end portion thereof extending outwardly from the surface bearing and defining downwardly facing and rearwardly facing surfaces which intersect at a supporting edge, said supporting edge lying in a plane which extends normal to the surface bearing and normal to said marking edge and which plane also includes the blade edge when the same is disposed normal to the marking edge, whereby the supporting edge and the surface bearing engage adjacent surfaces of the rafter board and the supporting edge defines a swing axis about which the body member is moved until the blade engages the rafter board.

References Cited in the file of this patent UNITED STATES PATENTS Mabye July 14, 1891 Callahan Dec. 2, 1902 Benskin Oct. 18, 1904 Johnson Jan. 8, 1907 Galford Jan. 19, 1937 Tracy Aug. 20, 1940 Smith June 30, 1942 Witter Jan. 25, 1944