US858913A - Drafting instrument. - Google Patents

Description

110.858.913.l PATENTEDJULY2.1907. RJG. SAUBR.

DRAPTINGINSTRUMENT.

APPLICATION FILED .141", 30, 1907.

I No. 858,913.

UNITED' STATES PATENT oEEIeE;

EoBEE'r c. SAUEE, or LOUISVILLE, KENTUCKY.

Specification of Letters Patent.

Patented July 2, 1907.

Applicant.. un num; 30.1907. stl-a1 nq. 354,819.

To all whom it my'ocmeerm Be it known that I, Bonner G. Sauna, a citizen of the United States of America, residing at Louisville, in the county of Jefferson and State of Kentucky, have invented new and useful Improvements in Drafting Instruments, of which the following is a specification.

This invention relates to a combination drafting instrument whereby straight or .curved lines, circles, and lines at various angles can be conveniently and readily made or arcs and langles of any degree accurately and quickly measured. y

The invention has for one of its objects to provide an instrument of this character -in which the moans for accomplishing the various operations above mentioned is combined with a T-square ot approved construction.

A- further object of the invention is the provision of a T-square upon which is slidably mounted hingedly connected scale blades whereby circles or arcs of -circles of various radii, lines at any desired angle and arcs and angles may be measuredin degrees with great facility without the use of the usual divider compass,

y beam compass, triangles and protractors.

Another object of the invention is to improve and simplify the construction and operation of devices of this character' so as to be comparatively easy and inexpensive to manufacture, readily and conveniently Inanipulated, composed of few parts and designed to enable the scale blades to be folded under thelblade of aI T-square out of the way when not in use.

With these objects in view as will'appear as the nain elevation. Fig; 3 is a vertical transverse section on line 3-3, Fig. 1, dmwn on a slightly enlarged scale. Fig. 4 is a similar section on line 44,.Fig. 1.

Corresponding parts are indicated by similar reference characters through the several views of the drawings. w

Referring to the consisting of the usual head 2 and the`blade 3, which is preferably a steelcasting secured to the head l by screws or other suitable fastenings 4. The blade 3 is provided adjacent therruling edge 5 with a slot 6 that extends approximately the full length thereof. The under side of the blade is formed with longitudinal ribs 7 which, besides serving to reinforce and stiffen the blade, raise the blade off the drawing board 'so as to accommodate the scale blades when the latter are folded drawing, 1 designates a 'J3-square into an inoperative position, as when they are not rcqui'red and the instrunient is to be used as an ordinary Employed in combination-with the T-square is a pair of scale blades 8 and 9 having their adjacent ends arby the rivet 10. These blades have perfectly straight and smooth -longitudin'al edges and any desired system or systems of divisions or scales may be applied thereto. Each blade is provided` with an elongated rectangular slot 11 extending approximately the full length thcreof. Arranged to slide in one or the other of these slots 11 is a pen or pencil holder designated generally by 12. This holder comprises an axially bored screw or bolt 13 having a rounded portion 14 that fits slidably in the slot 11 and engaging the thread 15 is a nut- 16 bearing on one side of the blade 8 or 9 with the lieadl'llof the screw bolt bearing on the opposite side. ,By loosening the nut 16 the pencil holder can be adjusted to'any desired position and then secured in place. by tightening the nut.

To change the pencil holder from one scale blade to they other it is, of course, necessary to unscrew thenut entirely and take out the bolt and adjust the holder to the desired blade. The rivet 10 is preferably. provided with an opening 18 for facilitating the obtaining of centers and other points in the various operations of the.

instrument. l p y The scale blade 8 is slidably and pivotally mounted on the blade ofthe T-square by means oi a slide 19 and a pivot lug on the blade 8 passing through the slide. The slide comprises a semi-circular plate having lugs 20 curled downwardly toenter the slot 6 of the T-square blade as best shown in Fig. 2, the fit being ysuch that a perfectly rigid and accurate movement of the slide 19 is possible. Adjacent the periphery of the slide 19 are arranged degree marks designated by 21 after the fashion of an ordinary protractor. The scale blade 8 which is preferably cast steel has the pivot lug 22 formed integral therewith and projects upwardly through the slide 19 and throgh a Hat quadrant shaped plate 23. The lug 22 is transversely apertured to receive the pivot pin 24 for the clamping cam 25, said cam being provided with a lever 26 for conveniently operating the cam. This cam forms a clamping means whereby the scale blade 8 and slide 19 are securely fastened in any desired position of adjustment. The quadrant 23 has an index mark 27 coinciding with its centerline which coperates with the scale 21 of the slide 19 for adjusting the scale blades to any desired angle and for measuring an angle or arc in terms of degrees. In the center line of rangedin overlapping relation and hngedly connected y the quadrant 23 is a depression 28 for receivingthc laterally curved end of the cam lever 26, as best shown in Fig. 2.

From the foregoing description taken in connection with the accompanying drawing, the advantages of the construction and of theI method of operation will be T-square the blade 9 is first folded over the blade 8 and then the cam 25 is unclamped so that the scale blades can be swung under the T-square blade. The clamping cam is then tightened so as to holdthe blades in place. Horizontal lines can then be drawn by the use ofthe 'll-square blade in the usual manner. When it is desired to draw vertical lines or lines between the vertical and horizontal, the scale blades 8 and 9 are employed. i To draw circles of large radii the pivot 22 is used at. its center and a pencil' is placed inthe holder l2 and the lines drawn by swinging thescales 8 and 9 as 'a single member or unit around the pivot 22. By -adjustng the holder l2 back or forth on either one of the scale blades concentric circles can be described. ln order to draw circles of small diameters `the opening 18 inthe rivet 10 is used as a center and the blade 9 is swung around to describe the circle while the pencil is held in the holder 12. By shiiting the holder concentric circles or arcs can thus be described. To measure an angle or the length of an arc or circle in degrees the! instrument is. adjusted so that the axis ot the pivot 22 will coincide with the center of the arc or angle and then the scale blade or blades are manipulated after first loosening the clamping cam. For instance, "the scale blade is moved so as to coincide with one end oi the arc to be measured,and then the quadrant plate '23. is adjusted so that the lever 26 will enter the depression 28 when the cam is tightened. The position of the index line 27 on the quadrant is noted with relation to the degree scale 21. The clamping cam is then loosened and the scale blade adjusted to the opposite end of the arc to be measured. The quadrantplate 23 is again shifted so that the clamping cam can be tightened and the lever 26 thereof enter the depression 28 of the quadrant plate.. The position of the index line 27 with respect to the scale 21 is noted so that by a simple computation the length of thearc in degrees is obtained.

From the foregoing it will bel seen that the instrument is adapted to a large variety oi uses, and obviates the need oi several ordinary draiting implements, such as triangles,scale rule, protractor, Compasses and the like.

I have described the principle of operation of the invention together with the apparatus which I now consider to be the 'best embodiment thereof, and l desire to nation ot a Tsquare,a slotted blade plvotaliy and slidably mounted on the blade of the square, and u. pencil holder slidable on the`siotted blade, said holder comprlsing a longitudinally bored screw bolt, and a nut engaging the bolt.

2. In an instrument of the class described, rthe comblnation of a T-square having a slotted blade, a slide movable on the top surface ot the blade and provided with Vmeans engaging in the slot of the Tsqusre blade, a pair of hlngedly connected scale blades pivotally mounted on the slide, and a clamping means for adjustably securing the slide and scale blades to the T-square blade.

3. In an instrument of the class described, the comhlnation of s. slotted blade provided with longitudinal ribs on its under surface. and alongitudinai slot, a slide movable on the top surface ot the blade, s. blade pivotoliy mounted on the slide and arranged to fold under the slotted blade, and a clamping means for sdjustablysecuring the slide and second lblade ln ilxed position on the slotted blade.

4. in an instrument of the class described, the combination of a 'l2-square having a longitudinally slotted binde,

'a slide on the blade having portions engaging the slot of the latter, a second blade, a pivot thereon extending through the slide from the underside of the square blade, a plate -on the slide'through which the pivot extends, a clamping cam fuicrulned on the pivot for clamping the slide and second blade to the square blade.

5. in an instrument o! the class described, the combi nation of a T-square having a slotted blade, o. semi-circular slide movable along the blade and provided with portions engaging in the slot of the latter, a degree Ascale on the slide adjacent the periphery thereof, a plate movubly mounted on the sllde and provided with an index mark and having a depression in line with said mark, a slotted secondary blade disposed under the square blade and provided with a lug extending upwardly through the slide sind plate, a clamping device on the ing adapted to engage in the depression of the plate, and a pencil holder adjustubly mounted on the secondary blade.

6. In an instrument o! the class described, the combination'of a 'il-square having a slotted blade, a slide guided by the slot, a slotted blade pivotnliy mounted on the slide, a third slotted blade arranged with one end overlapping the second blade, a hinge connecting the overlapping portions of said blades and provided with 'an opening, and a pencil holder adapted to be used interchangeably on either of the hingedly connected blades.

In testimony whereof, I ailix my signature in presence of two witnesses.

ROBERT c. sauna.

Witnesses:

JOSEPH H. Wnisnunnnosm, GEORGE W. Lucas.

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