US1365991A

US1365991A - Combined fixed-angle square and protractor

Info

Publication number: US1365991A
Application number: US279689A
Authority: US
Inventors: Alfred H Helden
Original assignee: Individual
Current assignee: Individual
Priority date: 1919-02-28
Filing date: 1919-02-28
Publication date: 1921-01-18
Anticipated expiration: 1938-01-18

Description

A. H. HELDEN. comsmen FIXED ANGLE SQUARE AND PHOTRACTOR. APPLICATION FILED FEB. 28, 1919. 1,365,991, Patented Jan, 18, 1921.

3 SHEETS-SHEET 1.

34, a ("IMAM/M01 woe/nap A. H. HELDEN. COMBINED FIXED ANGLE SQUARE AND PROTRACTOR.

APPLICATION FILED FEB'. 28, I919.

Patented Jan. 18, 1921.

3 SHEETS- SHEET 2.

Mow M1 0 A. H. HELDEN. COMBINED FIXED ANGLE SQUARE AND PROTRACTOR. APPLICATION F|LED fEB.28,19l9.

1,365,991, Patented Jan. 18, 1921.

3 SHEETS-SHEET 3.

Gum/W 0 PATENT OFFICE.

ALFRED HELDEN, OF KANSAS CITY, MISSOURI.

COMBINED FIXED-ANGLE SQUARE AND PRO'IRAGT'OR.

Specification of Letters Patent.

Application filed February 28, 1919. Serial No. 279,689.

To all whom it may concern:

Be it known that I ALFRED H. HELDEN, a citizen of the United tates, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in Combined F ixed- Angle Squares and Protractors; and I do doclare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates togeometrical instruments, and it relates more specifically to an improved combined fixed-angle square and protractor. One object of the invention is to provide a device of this character which is extremely convenient and thoroughly practical for laying off angles on rafters, braces, stairs, etc.

A further object is to provide an adjustable device of this character with which the angles of both thetop .and bottom cuts of a rafter may be laid off while the adjustment of its parts remains unchanged. 1

Another object is to provide a device of this character which simultaneously indicates the degree of angularity and the pitch or rise in inches per foot.

Another object is to provide a device of this character which comprises a square having an improved fraction-index thereon to coact with the base in indicating the fractional pitch of one line relative to another line.

Other objects and advantages may become apparent to persons who read the ollowing details of description in connection with the accompanying drawings, in which:

Figure 1 is a side elevation showing my improved geographical instrument applied to a beam which is to be laid off and scribed.

Fig. 2 is an enlarged front elevation of the device, the blade andwing of the square being broken off. i I

Fig. 3 is an enlarged rear elevation of the device, except being shown withthe square in a different position from that shownin Fi .2.

ig. 4 is a sectional view along the line 4-4 of Fig. 2.

Fig. 5 is a sectional view along the line 5--5 of Fig. 2.

Fig. 6 is a sectional view along the line 6-6 of Fig. 2.

Fig. ,7 is a detail view illustrating the angular element or square detached from the base of the device.

Referring to these drawings in detail, in which similar reference characters correspond with similar parts throughout the several views, the device broadly consists of a base 10, an angular element or square 11, and a pivot 12 which unites the square with the base. The base preferably consists of two

plates

13 and 14 which are L-shaped in cross section, and a flat plate 15, the latter being embraced between the

plates

13 and 14, and these three parts are secured together by rivets 16 or by other appropriate means. Each of the

members

18 and 14 is provided with a flange which extends from end to end thereof, and the surfaces 17 of these flanges are straight and disposed in the same plane.

Each of these surfaces 17 constitutes a working face of the base member as will be seen by reference to Fig.1. The bar or plate 15 is formed with a semi-circular recess 18 around which is a segmental or arcuate scale 19, and each of the

members

13 and 14 is formed with an aperture or bearing 20 which is concentric with the arcuate scale 19. One segmental portion of the scale 19 is provided with graduations and numerals to indicate degrees of angularity, as shown at 21, another'portion of the scale being graduated and numbered to indicate units of linear measure, inches being indicated in the present instance, as shown at 22.

Thesquare or angular element 11 has its outer edges 23 and 24 parallel with the corresponding inner edges 25 and 26, and the outer edges, if produced, would pass through the center of the segmental scale 19, this center being spaced from the working faces 17 a distance equal to the distance between the edges 23 and 25 of the square. The inner edge 27 of the plate 15 is also spaced from the working faces 17 a distance equal to the distance between the edges 23 and 25, so that when the edge 23 is against the edge 27, the edge 25 is flush with the working faces 17, and the edge 24 is at right angles to the length of the faces 17, as here shown in Fig. 3.

The angular element 11 is formed with an index element 28 which extends outwardly therefrom and terminates in two indexing points or indicating pointers 29 and 30. The index 28 is disposed within the semi-circular recess or aperture 18, and each Patented Jan. 18, 1921. i

indexing point is in alinement with one of the outer edges 2324:, the other indexing point being in alinement with the other one of said outer edges. The pivot 12 extends through an aperture 31 at the apex of the angle formed by producing the edges 23-24, and the center of this aperture is directly between the point 29 and the edge 2 f, being also directly between the point 30 and edge 23. It will be seen, therefore, that when the instrument is adjusted as shown in Fig. 3, the indexing point 30 registers with a point on the scale which may be properly termed the zero point of the arcuate 0r segmental graduation 21. However, this zero point for the edge 26 is also the point for the edges 23 and 25, that is, as shown in Fig. 3, when the indexing point 30 registers with the mark at the beginning of the scale or graduation 21, it indicates that the edge 26 is flush or parallel with the working faces 17 and that the edges 23 and 25 are at right angles thereto; but, when the indexing point 30 is moved upward along the scale 21 it indicates the degree of angularity between the working surfaces 17 and the edges 24 and 26. Although I have spoken of the index or graduation 21 in the singular, it will be seen, by referring to Figs. 2 and 3, that the scale 21 is duplicated on opposite sides of the plate 15, and the same is true regarding the scale 22. Referring now more specifically to the scale or graduation 22, it is seen that the same is arranged for indicating the amount of pitch as referred to the surfaces 17 and the edges 23 and 25. In other words, this scale indicates the number of inches rise for each foot of run along a beam to be laid off. Although this scale indicates but 18 inches of rise, it will be seen that the scale may be increased to 24: inches rise, if desired, without conflicting with or overlapping the scale 21.

The square is provided with outwardly I diverging lines 32 which coact with the working faces 17, in a well known manner, for indicating the fractional pitch, thus pitch, 1]; pitch, pitch, etc., as indicated at 33. In order to avoid confusion of the fractions 33, with the lines 32 which are not intended to be designated by these fractions, the latter are placed in a column at a distance from the terminals of the lines 32, and curved lines 34 connect the respective fractions with the lines 32 intended to be designated, respectively, thereby.

The pivot 12 is preferably in the form of a screw, and a wing nut 34 is provided on the screw and cooperates therewith and with the somewhat yieldable bars 1.3 and 14c for effecting a clamping or frictional engagement with the opposite sides of the square, so that the latter may be held thereby in its respective adjustments. Y From the foregoing disclosure of the construction and operation of the device, it will be seen that this device is useful in many relations and for many purposes, including the laying off of beams according to angular measure, or according to a pitch in inches per foot, or according to f actional pitch. This enables a person to use the device, without the necessity of resorting to mathematics where the pitch is given in degrees 0 l' angular measure, or in inches per foot. or in fractions.

In order that the utility of this device may be extended still further, a spirit level 35 is provided, the index elements of this level being arranged to register when the surfaces 17 are level. By this means, the device may be employed for ascertaining whether a beam or surface is plumb, level. or inclined at any angle, the degree of inclination being dete mined by the cooperation of this level with the indexing points and other features of the instrument.

Although I have described this embodiment of my invention very specifically, it is not intended to limit this invention to these exact details of construction and arrangement of parts, but I am entitled to make changes within the scope of the inventive ideas disclosed in the foregoing description and following claims.

What I claim as my invention is:

1. In a geometrical instrument, a base provided with a working face and a segmental scale having its center spaced from said face, an element having straight-edged blades fixed at an angle to each other, this element being pivoted at the intersection of the outer edges of said blades to said base at the center of said segmental scale, said element having an indicating pointer in alinement with one of said edges and movable over said scale.

2. The structure defined by claim 1., and a second indicating pointer in alinement with another one of said edges which is at an angle to the first said one of the edges, said scale comprising separate sets of graduations that coact with said edges respectively.

3. The structure defined by claim 2, one of said sets of graduations consisting of units of length, the other of said set-s consisting of units of angular measure.

4. The structure defined by claim 3, one of said sets of graduations including a zero on a line that intersects said working face at right angles and also intersects the pivotal axis of said adjustable element. said base and adjustable element being provided with means to confine movement of one of said indicating pointers within the arcuate limits of its set of graduations.

5. In a geometrical instrument, a base provided with a working face and a segmental scale, and an adjustable element iiicluding two outer edges fixed at right angles to one another and two inner edges parallel with said outer edges respectively, said adjustable element also comprising an indicating pointer in alinement with one of said outer edges, said adjustable element being pivotally connected to said base at a point at the center of curvature of said scale, said center being spaced from said Working face a distance equal to the distance between two of the parallel edges of said adjustable element so that the inner one of these two edges is flush with said working face when the outer one of the other two parallel edges is at right angles to said working face, said scale having a zero in the position to register with said indicating pointer when the last mentioned outer one of these edges is at right angles to said Working face.

In testimony whereof I have hereunto set my hand.

ALFRED H. HELDEN.