US2562224A - Protractor - Google Patents

Description

J y 1951 w. B. WEYRICK 2,562,224

- PROTRACTOR Filed March 29, 1945 Imlllllllil INVENTOR. We: r? 5. W22 Heir I? fforng,

H from the right of Figure 1.

Patented July 31, 1951 UNITED STATES PATENT OFFICE PROTRACTOR Warren B. Weyrick, Akron, Ohio Application March 29, 1945, Serial No. 585,534

' 4 Claims. (01. 3375) This invention relates to protractors. An object of the invention is to provide an improved protractor of simple compact construction and by which readings of angles may be readily made with optimum accuracy.

Anotherobject of the invention is to provide and the-accompanying drawings.

.Of the accompanying drawings: Figure 1 is a front elevational view of a protractor embodying the invention.

Figure 2 is a side elevation thereof as viewed Figure 3 is a view similar to Figure 1, but

illustrating the protractor in another position of use for measuring an angle.

Figure 4 is a view similar to Figure 1 illustratinga modified vform of the invention.

Figure 5 is an enlarged cross-section taken substantially on line 5-5 of Figure 4.

Figure 6 is a view similar to Figure 1 illustrate ing another modified form of the invention.

Figure 7 is a fragmentary view of the device one end of plate Ill and equidistant from side edges H and I2 thereof.

Plate I4 is provided, outwardly of pivot I3,

' with a straight-edged portion l5 which forms an outside angle with one side ed e H and which .may be of length substantially equal to the Width of plate H], as shown. The lateral end of plate I4 adjacent said side edge ll may be rounded as shown so as not to project beyond a radius from pivot l3 equal to the distance from the pivot to the side edge. Plate [4 may have the other lateral end thereof extended to provide a straighted'ged portion l6 which projects outwardly of straight side edge 12 a substantial distance, this straight edge [6 being in parallelism with edge 15 and forming an inside angle with said side edge l'2. The edges H and I2 of plate In and edges l5 and IBof member M, respectively, being in parallelism it will be seen that all angles which edge portions l2 and I6 make with each other, as member I4 is pivoted relatively of plate III, will be equal to corresponding angles formed between edge portions II and 15. The pivot end of plate I0 is cut back at angles from a radius about pivot 13, as indicated at lob and I00, so that the plate will not project beyond straight-edged portion 15 in any angular position of adjustment of plate 10 and member l4. The edge portions [5 and I6 of plate 14 preferably are substantially close to pivot 13 for compactness and simplicity of design.

The member 14 may be shaped to provide a narrow indicator or finger 20 which extends longitudinally of plate Ill to adjacent the end thereof opposite to pivot l3, the free end of this indicator having a mark 2! or other means thereon for indicating, on a scale 22 marked on plate In, the various angles between adjacent straight edged portions, as previously described. The indicator, as shown in Figure 1, is set to read zero when the straight edged portions are at right angles to each other, and-the scale is marked to indicate angles within a range of ninety degrees plus or minus fifteen degrees, this range being satisfactory for a maximum of practical uses of the device, as by mechanics, engineers, draftsmen, inspectors, checkers and many other skilled craftsmen; Itwill be seen however, that the range of readings may be increased, but possibly at the expense of increasing the proportions of the device. To obtain maximum range of degrees on the scale 22 the zero mark is equidistant from side edges II and I2 of plate I0, that is, it is on the longitudinal center line of said plate. An aperture 23 or other suitable non-skid means is provided adjacent the free end of the indicator to facilitate swinging member 14 relatively of plate I0, about pivot l3.

For releasably locking member 14 to plate ID in any position of angular adjustment thereof there may be provided on indicator 2|], intermediate the free end thereof and pivot I3, a slotted enlargedportion 25 through a curved slot 25 of which extends a threaded pin 26 which is secured to plate I0, the pin 26 having a nut 21 threaded thereon for clamping said member and plate together. The slot 25 is curved on a radius from pivot l3.

In the use of the invention described above as for checking the outside angle of a strip of ninety-degree angle-material, the nut 21 is loosened andthe device is applied to the material, as indicated in chain-dotted lines in Figure 1, after which the nut may be tightened to clamp plate and member 14 together, the angle being directly readable on scale 22. Conversely, the angle may be first set on the scale and the parts clamped together so that an angle strip or other part may be worked or formed to a desired angle. Likewise the same settings may be utilized for checking or transposing an inside angle. Figure 3 illustrates the device as set for reading an inside angle of greater than ninety degrees (seechain-dotted lines), or an outside angle of the same number of degrees.

In Figures 4 and 5 is shown a protractor substantially like that shown in Figures 1 to 3, except that member Ma, corresponding to member 14, is made in two parts, the part IBa for-the projecting straight-edged portion being pivoted to member Ma at Mb. A detent 30 is provided on part lGa, in spaced relation topivot Mb, for releasable engagement in either one or other of two depressions 3i and 32 in member I 4a, to retain said part either in an operative position thereof shown in chain-dotted lines in Figure 4 or in a retracted inoperative position, as shown in Figures 4- and 5. The operation of this modified form of the invention is otherwise the same as previously de-- scribed, like parts being given'like numerals with a sufiix a except as otherwise noted. Referring to Figure 6 there is illustrated another modified form of the invention, designed particularly for measuring inside angles. A plate 40 is of trapezoid shape providing one straight lateral side edge 4|, the width and shape of the plate otherwise being as desired to measure within a desired range of degrees, as will be described. Pivoted at 42 at one corner of plate 46, closely adjacent edge 4|, may be a quadrantshaped plate or member 43, one straight edge 44 of which forms an outside angle with said edge 4|. A narrow indicator or finger extends from plate 43, angularly of' edge 4!, to' adjacent the other end of plate 40 and is provided with a mark The scale shown is designed to For clamping the device v42, said pin having a nut 4"! threaded thereon and operable as previously described.

In Figure '7 is shown a protractor which is similar in all respects to that illustrated in Figures 1 and 2, except that plate I4 is rounded at I40 and Md on a radius from pivot 13 equal to half the width of plate [4, so that bearing surface will be assured beyond the pivot ends of side edges I I and I2 and in alignment therewith.

Thus has been provided a novel protractor which accomplishes the stated objects of the invention. Other modifications thereof may be resorted to without. departing from the spirit of l the invention or the scope of the appended claims.

What is claimed is: l. A protractor comprising a plate providing opposite straight lateral side edges in parallelism,

a member superposed on said plate and being pivoted thereto at a point substantially closely adjacent one end of the plate, said member having an outer straight edge portion longitudinally outwardly of said pivot to lie free and unob- ,structed' beyond the pivot end of said plate and laterally across the same within a predetermined range'o'f various-angularly adjusted positions of l, saidmember on said pivot with respect to said plate;"sa'id outer straight edge portion of said 4 member extending in lateral direction from said pivot toward one of said straight lateral side edges of said plate but not beyond said side edge in any said angularly adjusted position of said plate and member and thereby defining a variable outside angle corner on the protractor for gauging inside angle corners, said member having an inner straight edge portion parallel to said outer straight edge portion thereof projecting beyond the other said straight lateral *side edge of said plate and thereby forming therewith an inside angle corner which is variable correspondingly to the angles of said outside angle corner of the protractor for gauging outside angle corners, and

'means-on said plate and member for indicating the angular variations of said inside and outside angle corners of the protractor, said pivot being equidistant from said lateral side edges of said plate, the edge portions at said one end of said plate being inwardly divergent from a point at a. radius from said pivot.

2. A protractor comprising a plate providing opposite straight lateral'side edges in parallelism, a member superposed on said plate and being pivoted thereto at a point substantially closely adjacent one end of the plate, said member having an outer straight'edge portion longitudinally outwardly of said pivot to 'lie free and unobstructed beyond the pivot end of said late and laterally across the same within-a predetermined range of angularly adjusted positions of I said member on said pivot with respect to said plate, said outer straight edge portionof said member extending in lateral direction from said pivot toward one of said straight lateral side edgesof said plate but not beyond said side edge in'any said angularly adjusted position of said-plate and member and thereby defining a variable outside angle corner on the protractor for gauging inside angle corners, said member having an inner straight edge portion parallel to said outer straight edge portion'thereof' projecting beyond the other said straight lateral side edge'of said plate and thereby forming therewith an inside angle corner which is variable correspondingly to the anglesof said outside angle corner of the protractorfor gauging outside angle corners and means on said plate and member for indicating the angular variations of said inside and outside angle corners of'the protractor, .the edgeJportions of said one end of saidplatebeing inwardly divergent from a point at a radius fromsaid pivot, said pivot being equidistantfrom said .lateral side edges of said plate, said memberihaving arcuate portions on a radius from said pivot equal to half the distance between said side edges.

3. A protractor comprising a plate providing opposite straight lateral side edges inparallelism, a member superposed on said plate and being pivoted thereto at a point substantially' closely adjacent oneend of the plate, .said member having an outer straight edge portion longitudinally outwardly of said pivot to lie free and unobstructed beyond the pivot end of said.- plate and laterally across the same within a predetermined range of various angularly adjusted'positions ofsaid member on said pivot'with respect to said plate, said outer straight edge portion of said member extending in. lateral: direction from said pivot toward one of said straight lateral side edges of said plate but not beyond said side edge in any angularly; adjusted position of said plate and member and therebydefining a variable outside angle-comer OII tBQ'PID- tractor 'forgauging inside: an le com rsg fiq member having an inner straight edge portion parallel to said outer straight edge portion thereof projecting beyond the other said straight lateral side edge of said plate and thereby forming therewith an inside angle corner which is variable correspondingly to the angles of said outside angle corner of the protractor for gauging outside angle corners, and means on said plate and member for indicating the angular variations of said inside and outside angle corners of the protractor, said inner straight edge portion of said member comprising a separate part pivoted to the member, releasable means being provided on said member and said separate part for selectively releasably retaining said separate part in outwardly projecting position or in inwardly folded position.

4. A protractor comprising a plate providing opposite straight lateral side edges in parallelism, a member superposed on said plate and being pivoted thereto at a point substantially closely adjacent one end of the plate, said member having an outer straight edge portion longitudinally outwardlyofsaid pivot to lie free and unobstructed beyond the pivot end of said plate and laterally across the same within a predetermined range of various angularly adjusted positions of said member on said pivot with respect to said plate, and said outer straight edge portion of said member extending'in lateral direction from said pivot toward one of said straight lateral side edges of said plate but not beyond said side edge in any angularly adjusted position of said plate and member and thereby defining a variable outside angle corner on the protractor for gauging inside angle corners, said member having an inner straight edge portion parallel to said outer straight edge portion thereof projecting beyond the other said straight lateral side edge of said plate and thereby forming therewith an inside angle corner which is variable correspondingly to the angles of said outside angle corner of the protractor for gauging outside angle corner, and means on said plate and member for indicating the angular variations of said inside and outside angle corners of the protractor, said pivot being substantially centrally from said lateral side edges of said plate, the edge portions at said one end of said plate being inwardly. divergent from a point at a radius from said pivot.

WARREN B. WEYRICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 70,547 Graham Nov. 5, 1867 511,746 Bates Jan. 2, 1894 685,372 Duncan 1- Oct. 29, 1901 1,455,708 Brown May 15, 1923 2,033,626 Bozzer June 4, 1935 FOREIGN PATENTS Number Country Date 16,708 Great Britain Sept. 19, 1892 218,135 Great Britain July 3, 1924 357,925 Great Britain Oct. 1, 1931

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