US3273246A

US3273246A - Adjustable t-square

Info

Publication number: US3273246A
Application number: US378699A
Authority: US
Inventors: Alfred W Siberini
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-06-29
Filing date: 1964-06-29
Publication date: 1966-09-20
Anticipated expiration: 1983-09-20

Description

Sept. 20, 1966 A. w. SIBERINI ADJUSTABLE T-SQUARE Filed June 29, 1964 FIG. 4 FIG 8 ,42 la 22 Z //////I|||1V////////,,. 2/

INVENTOR. ALFRED W. SIBER/N/ ATTORNEY United States Patent 3,273,246 ADJUSTABLE T-SQUARE Alfred W. Siberini, 221 Ivy St., Kearny, NJ. Filed June 29, 1964, Ser. No. 378,699 10 Claims. (Cl. 33101) This invention relates to drafting apparatus, and more particularly, to a T-square with a blade universally adjustable with respect to its head.

T-squares are known in which the head is fixed with respect to its blade. They are also known in which each head is angularly movable with respect to its blade. In accordance with my invention, the head is not only adjustable 'angularly with respect to its blade, but the blade is longitudinally slidable with respect to the head when associated therewith in one position and also angularly movable with respect thereto when removed and -re-asso ciated with it in another position.

An object of my invention is to provide an adjustable T-square in which the blade is slotted and connected to the head by a thumb screw which when tightened holds it against angular and/or longitudinal movement with respect to said head.

Another object of my invention is provision of a T- square in which the blade may be slideably mounted with respect to its head when connected to one face thereof and rotatably mounted with respect to its head when connected to the other face thereof, one edge of said other face being semi-circular and angularly graduated as a protractor, the divisions thereof being readable through an aperture in the blade to thereby show the angular position of said blade with respect to its head.

A further object of my invention is the provision of an adjustable T-square in which the blade is graduated along its edges to function as a ruler and removable from its head.

These and other objects and advantages will become apparent from the following detailed description when taken with the accompanying drawings. It will be understood that the drawings .are for purposes of illustration and do not define the scope or limits of the invention, reference being had for the latter purpose to the appended claims.

In the drawings, wherein like reference characters denote like parts in the several views:

FIGURE 1 is a perspective view of an adjustable T- square embodying my invention, wherein the blade is connected to its head for angular movement therebetween.

FIGURE 2 is a view corresponding to FIGURE 1, but showing the head reversed with respect to its blade and connected thereto so as to prevent any angular movement therebetween.

FIGURE 3 is a plan of a head of the T-square, shown in FIGURE 1, after the blade has been removed therefrom.

FIGURE 4 is an edge elevational view of the head as from the bottom of FIGURE 3.

FIGURE 5 is a side elevational view of the thumb screw which holds the head and blade together in adjusted position.

FIGURE 6 is a side elevational view of a locking washer which may be used between the head of the thumb screw and the blade of the T-square when the parts are held together.

FIGURE 7 is a full-sized fragmentary plan of the upper or far end, of the blade of the T-square, as viewed in FIGURES 1 and 2, from the bottom.

FIGURE 8 is a full-sized section view of the blade on the line VIII-VIII of FIGURE 2, in the direction of the arrows.

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Referring to the drawings in detail, there is shown a T-square embodying my invention comprising a head or butt plate 11, one side of which is slotted as indicated at 12 and the other side of which has a series of angle or degree graduations 13 along a semi-circular edge portion 14. Edge portion 14 is semi-circular, or extends between 0 and degrees, and then its ends extend straight, as indicated at 15 and 16, perpendicular to a straight edge portion 17.

Associated with the head 11 is a blade or ruler portion 18, desirably generally trapezoidal in section, as indicated most clearly in FIGURE 8, except that the sharp edges along the lower face at the sides are defined by right angles rather than by acute angles, as would occur if the sloping or beveled sides 19 and 21 were continued to the extreme lower face. This is in the interest of accuracy so as to have at least a slight thickness at the drawing edges of the blade, rather than having said edges acute in angularity.

The blade section, as shown most clearly in FIGURE 8, corresponds with the section of the notch or slot 12 in the head, so that said blade may be slid into said notch and be snugly held therein against any angular movement with respect to said head, as viewed in FIG- URE 2. However, longitudinal movement between the head and blade is permitted by virtue of the longitudinal slot 22 extending the greater part of the length of the blade and of a width sufiicient to receive the shank 23 of a thumb screw 24. The head 25 of said screw is desirably knurled to facilitate application and removal.

The shank 23 of said screw 24, for reception in a threaded aperture 32 in the head 11, desirably passes through a washer 26, shaped as shown most clearly in FIGURES 1, 2 and 6; that is, with its peripheral edge beveled or sloping as indicated at 27. Said washer is shown disposed between the lower surface of the head 25 and the top surface of the blade 18. This construction allows the blade to be adjusted with respect to the head and then tightened in place on said head in an ad justed position. The edges of the blade 18 are graduated in inches, centimeters, or other desired unit of measurement, as illustrated, thereby adapting said blade to be used as a ruler either with or when separated from its head.

The blade 18, instead of being used in position where it extends perpendicular to the straight edge 17 of the head 11, may be removed from the slot 12, after unloosening and removing the thumb screw 24 and associated washer 26 from the threaded aperture 32, and the head reversed to the position of FIGURE 1 and reconnected by said screw 24 to the blade 18. Here angular adjustment therebetween is permitted, as between the head position shown in full lines, where the relationship is perpendicular, and that indicated with dotted lines, where the head 11 has been angled with respect to the blade 18. Such occurs when it is desired to use the head as a protractor for drawing a line along the blade at an angle other than perpendicular with respect to the straight edge 17 In order to accurately measure the angle through which this blade is swung with respect to the head, the upper or remote end of the blade as illustrated, has an aperture 28 desirably closed by a transparent plug 29, which may be formed of plastic material or the like. It desirably carries a hair line 31 engraved thereon so as to lie over a selected angular graduation for setting the blade with resepct to the head. For that purpose, the hair line 31 is desirably formed on the bottom of the blade plug 29, as viewed in FIGURES 1 and 2, it being noted, however, that the blade in FIGURE 7 is a view of the bottom, so the hair line 31 is there on the top and lies along a diameter of the plug 29 parallel to the side edges of the blade.

From the foregoing disclosure it will be seen that I have devised a useful T-square comprising a head 11, flat on one side, with one edge 17 straight and the other edge 14 curved or semi-circular and terminated by

straight portions

15 and 16 erpendicular to said straight edge 17. There is a blade 18 associated with said head 11 for completing the T-square. This blade has its side edges beveled, as indicated at 19 and 21, but desirably not completely to sharp drawing edges. It carries longitudinal graduations adapting it to function as a ruler or means for measuring the distance between the straight edge 17 and a selected position on a drawing board, for example. The head 11 has a threaded aperture 32, extending from one face to the other, lying midway on a straight line extending between the junctions of said terminating

portions

15 and 16 and the semicircular edge 14. The blade 18 has a slot 22, of a width corresponding with the diameter of the aperture 32 and the shank 23 of the thumb screw 24, which slot extends from near one end toward the other and terminates at the distance from the other end approximating the radius of said semi-circular edge 14. Said other end portion of the blade 18 has an aperture 28 desirably plugged by a piece of transparent plastic 29 desirably cylindrical and carrying a hair line 31 which normally lies over a selected angle graduation along the semi-circular edge of the head 11, so that the position of the blade with respect to the head may be set as desired, when the parts are assembled as viewed in FIGURE 1. When, however, the

thumb screw 24 is removed and the blade 18 taken from the head, fitted in the slot 12 and the screw shank passed through the slot 22 and threaded into the aperture 32 to hold the blade in place, as viewed in FIGURE 2, then it always stays square with respect to the straight edge 17 of the head. However, even then longitudinal adjustment of said blade 18 with respect to the head 11 is permitted, as from the position shown in full lines in FIGURE 2 to that indicated in dotted lines in said figure.

Having now described my invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes or modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.

I claim:

1. An adjustable T-square comprising a head flat on one side, with one edge straight, a blade associated with said head for completing the T-square, said head having a threaded aperture, extending from one face to the other, lying halfway between its ends, said blade having a slot closed at both ends and of width corresponding with the diameter of said aperture, a thumb screw with a threaded shank fitted through said slot and into said aperture for holding said blade in place with respect to said head, the other side of said head having a groove of section corresponding with that of said blade and into which the latter fits when removed from said screw, reversed and slid along the other side of said head, said groove being defined by side edges parallel to a plane through the axis of said aperture and perpendicular to said straight edge and said screw being removable and reinsertable in the head from the opposite face to hold the blade in place, so that said blade when so held in the groove will always be square with respect to the straight edge of the head.

2. An adjustable T-square as recited in claim 1, wherein the sideedges of said blade are beveled and the groove correspondingly dovetailed in section.

3. An adjustable T-square as recited in claim 1,

wherein another ide of said head is semi-circular but terminated by straight portions perpendicular to the straight edge and the threaded aperture lies midway on a straight line extending between the junctions of said terminating portions with said semi-circular edge.

4. An adjustable T-square as recited in claim 1, wherein the blade carries length graduations adapting it to function as a ruler.

5. An adjustable T-square as recited in claim 1, wherein said slot extends from near one end toward the other and terminates at a distance from the other end approximating the radius of said semi-circular edge.

6. An adjustable T-square as recited in claim 1, wherein another edge of said head is semicircular.

7. An adjustable T-square as recited in claim 6, wherein there are angle graduations along said semicircular edge, said other end portion of the blade having an aperture alined with said slot and through which said angle graduations are readable when said blade and head are secured together by said screw.

8. An adjustable T-square as recited in claim 7 wherein there is a transparent plug closing said aperture, and a hair line on said plug for reading the angular disposition of said blade with respect to the straight edge of said head.

9. An adjustable T-square comprising a head flat on one side, with one edge straight and the other semicircular but terminated by straight portions perpendicular to said straight edge, a blade associated with said head for complet-ing the T-square, said blade having its side edges beveled and carrying length graduations adapting it to function as a ruler, said head having a threaded aperture lying midway ona straight line extending between the junctions of said terminating portions with said semicircular edge, said blade having a slot of width corresponding with the diameter of said aperture, extending from near one end toward the other end and terminating at a distance from the other end approximating the radius of said semicircular edge, a thumb screw with a-threaded shank fitted through said slot and into said aperture, angle graduations along said semicircular edge, said other end portion of the blade having an aperture alined With said slot, transparent plug closing said aperture, a hair line on said plug for reading the angular disposition of said blade with respect to the straight edge of said head when said blade and head are secured together by said screw, the other side of said head having a dovetailed groove of section corresponding with that of said blade and into which the latter fits when removed from said screw, reversed and slid along the other side of said head, said groove having side edges parallel to a plane through the axis of said aperture and perpendicular to said straight edge.

10. An adjustable T-square comprising a head flat on one side, with one edge straight and the other curved, a blade associated with said head for completing the T- square, said blade having its side edges carrying length graduations adapting it to function as a ruler, said head having a threaded aperture extending through said head and lying midway of said head, said blade having a slot of width corresponding with the diameter of said aperture, extending from near one end toward the other end, a thumb screw with a threaded shank fitted through said slot and into said aperture, angle graduations along said curved edge, said other end portion of the blade having an aperture alined with said slot for reading the angular disposition of said blade with respect to the straight edge of said head when said blade and head are secured together by said screw, the other side of said head having a groove of section corresponding with that of said blade and into which the latter fits when removed from said screw, reversed and slid along the other side of said head, said groove having side edges parallel to a plane through the axis of said aperture and perpendicular to said straight edge and said screw being removable and reinsertable in the head from the side of the head having References Cited by the Examiner UNITED STATES PATENTS 9/1916 Cruzen 33-102 4/1917 Helden 33-102 6 1,636,637 7/1927 Hutchinson 33-102 1,655,638 1/1928 West 33-99 2,179,658 11/1939 Gallagher 33-103 X FOREIGN PATENTS 520,566 2/1921 France 347,360 8/1960 Switzerland.

LEONARD FORMAN, Primary Examiner.

1,243,786 10/1917 White 33-103 10 H. N. HAROIAN, Assisant Examiner.

Claims

1. AN ADJUSTABLE T-SQUARE COMPRISING A HEAD FLAT ON ONE SIE, WITH ONE EDGE STRAIGHT, A BALDE ASSOCIATED WITH SAID HEAD FOR COMPLETING THE T-SQUARE, SAID HEAD HAVING A THREADED APERTURE, EXTENDING FROM ONE FACE TO THE OTHER, LYING HALFWAY BETWEEN ITS ENDS, SAID BLADE HAVING A SLOT CLOSED AT BOTH ENDS AND OF WIDTH CORRESPONDING WITH THE DIAMETER OF SAID APERTURE, A THUMB SCREW WITH A THREADED SHANK FITTED THROUGH SAID SLOT AND INTO SAID APERTURE FOR HOLDING SAID BLADE IN PLACE WITH RESPECT TO SAID HEAD, THE OTHER SIDE OF SAID HEAD HAVING A GROOVE OF SECTION CORRESPONDING WITH THAT OF SAID BLADE AND INTO WHICH THE LATER FITS WHEN REMOVED FROM SAID SCREW, REVERSED AND SLID ALONG THE OTHER SIDE OF SAID HEAD, SAID GROOVE BEING DEFINED BY SAID EDGES PARALLEL TO A PLANE THROUGH THE AXIS OF SAID APERTURE AND PERPENDICULAR TO SAID STRAIGHT EDGE AND SAID SCREW BEING REMOVABLE AND REINSERTABLE IN THE HEAD FROM THE OPPOSITE FACE TO HOLD THE BLADE IN PLACE, SO THAT SAID BLADE WHEN SO HELD IN THE GROOVE WILL ALWAYS BE SQUARE WITH RESPECT TO THE THE GROOVE THEREIN AND THROUGH THE SLOT TO HOLD THE BLADE STRAIGHT EDGE OF THE HEAD.