US2247157A - Ruler - Google Patents

Description

June 24, 1941.. c. H. LITTLE' 2,247,157

RULER Original Filed May 5, 1936 2 LIIIIIIIII 4 ,40 2 L 1o mim 36 40 5610 a@ INVENTOR;

BY CHneLss L 771.5

ATTO E Patented .lune 24, i941 KURIER Charles H. Little, Cleveland Heights, Ghio, as-

signor of one-tenth to Charles Hubbard Little, Cleveland Heights, hio,

@riginal application May 3, 1936, Serial No.

62,144. Divided and this application .lune 22, 1939, Serial No. 280,561

'i Claims.

The present invention relates to drafting devices or instruments employed in drafting, and more particularly to a drafting ruler, either scale or straight edge. The present application is a Idivision of my copending .application Serial No. 62,144, filed May 3, 1936, which has matured into Patent No. 2,182,027.

`Numerous attempts have been made in the past, as evidenced by my own prior art patents and otherwise, to produce a stiff, durable, light, easily readable ruler for drafting purposes which would not warp and which woul-d be otherwise satisfactory. At a very great expense I have made hundreds of experimental rulers from Celluloid, various kinds of wood treated in numerous ways, different metals and alloys, specially drawn tubing or bars, and various kinds of stampings. in addition thereto, I have made numerous compound rulers comprising metallic and non-rnetallic cores encased or `enclosed in Celluloid, etc. But prior to the present invention neither I no-r others working along the same line have been able .to produce an entirely satisfactory drafting ruler embodying the aforesaid advantages.

An object of the present invention is the provision of a novel drafting device or ruler which will be light, stiff, durable, and easily readable in the event graduations are marked thereon, which will not warp, and which will be otherwise satisfactory for `the purpose intended.

Another object of the invention is the pr-ovision of a novel drafting device or ruler comprising a metal body having edge strips formed of a plastic molded thereon and mechanically interlocked therewith.

`Other objects and advantages of the present invention will be apparent to those skilled in the art to which the invention relates from the following description of the preferred embodiments thereof, described with reference to the accompanying drawing forming a part of Ithis specification, in which similar reference characters designate corresponding parts throughout the several views, and in which Fig. 1 is aplan view of a drafting device or ruler embodying the present invention.

Fig, 2 is a fragmentary perspective view showing the ruler in section on the line 2-2 of Fig. 1.

Figs. 3, 5, 7, and 9 are views similar t-o Fig. 2, each showing a different modified construction of the ruler shown in Figs. 1 and 2.

Figs. 4, 6, 8, and 10 are sectional views tak-en approximately on the lines li-i, 6 6, 8-3, and lll-l0 of Figs, 3, 5, 7, and 9, respectively.

The drafting ruler A shown in Fig. 1 is of the type ordinarily referred to as a drafting scale and is especially adapted for use with drafting machines of ythe type sho-wn in either of my United States Patents Nos. 1,999,289 or 1,909,291. The parallel or ruling edges of .the scale are beveled as clearly shown in Fig. 2, and provided with :suitable graduations, etc. Provision is made for chucking the device to the chuckV or ruler supporting arm of a draf-.ting machine, by providing Iopposite ends thereof with chuck-s it adjustably secured thereto as by screws i l. The two chucks shown permit lthe ruler to be reversed, that is, 'either end may be chucked to the chuck-arm of Ethe drafting machine, as is the usual pr-actice. vThe chucks are preferably made of iduralumin provided with an oxide coating produced by a commercially known electrolytic process. This treatment produces a non-glare, durable surface Iand one which will not soil the drawing paper or .surface upon which the ruler is used.

In the embodiment of the invention shown in Figs. l and 2, the drafting device or ruler shown there-in, designated generally by the reference character A, comprises a body portion i2 having a .top beveled, outwardly taper-ing side edge portions i3 provided with edge strips ill secu-red thereto. The body portion i2 is preferably made of duralumin and extends from the upper to the lower side of the ruler proper. The exposed surfaces of the body portion l2 are preferably provided with an oxide coating of the character referred to above. The edge strips ld are preferably made of a plastic molded 'in position and mechanically interlocked with the edge portion I3 by transversely extending cooperating tongues and grooves.

The edge strips Il are preferably made of a polymerization product of a vinyl compound, 4such as, vinyl chloride, vinyl acetate, or vinyl benzine. These plas-tics have characteristics which adapt them particularly to the present use. They do not shrink or warp and are durable and easy to clean. The vinyl acetate is permanently nearly Water white Iand when the edges of the ruler are made therefrom they can be made transparent, in which event, the graduations, if employed, may be placed on the underside. Cornmercially known plastics sold under the trade names Vinolytef Vietrcf Ga-lva, etc., are suitable for the present purpose. Plastics ma de of the polymerization products of vinyl compounds can be molded at relatively low temperatures and pressures and have a very l-ow and constant mold shrinkage, making it possible lto mold graduations thereon accurately and cheaply. The characteristics of these plastics are also such that graduations and characters may be readily cut therein. These materials are tough and flexible without being brittle or unduly hard, which qualities give a superior wear resistance. They also feel well lto the touch, keep -clean and can be tinted various colors.

Referring specifically to Fig. 2, it will be seen that the beveled edge portions I3 of the ruler body I2 are provided with a plurality of longitudinally extending alternating dove-tailed grooves I5 forming a plurality of longitudinally extending tongues I6 and that the edge strips I4 are securely mechanically interlocked with the beveled edge portions i3 by cooperating alternating tongues and grooves formed on the underside of the plastic edge strips. In the preferred embodiment of the invention shown, the mechanical interlock between the edge strips Ibi and the beveled edge portions tongues and grooves ruiming lengthwise of the ruler, which hold the edge strips Id against movement, particularly crosswise of the ruler body, but it will be apparent that other forms of mechanical interlocks may be employed in addition to the longitudinal grooves shown in Figs. 1 and 2.

Figs. 3 and i show a ruler B similar in construction to the ruler A shown in Figs. 1 and 2,

except that the beveled edge portions I8 of the body portion I9 are provided with transversely extending dove-tailed grooves Zlladjacent the ends" of the ruler in addition to the longitudinally extending grooves 2l similar to the grooves I5 in Fig. 2. edge strips 22 against lengthwise movement. If desired, the transverse grooves may be formed at intervals along the entire length of the ruler rather than adjacent to the ends only.

Figs. 5 and 6 show a ruler C illustrating another method of supplementing the longitudinally extending tongues and grooves for securing the edge strips to the beveled edge portions of the ruler body. As shown in these iigures, the edge strips 25 are secured to the beveled edge portions 2t of the ruler body 2l by metal rivets 28 located adjacent the ends of the ruler in addition 'to the mechanical interlock between the edge s 1ips and the ruler body formed by the longitudinally extending grooves 29 similar to the grooves I5 and 2| previously referred to.

Figs. '7 and 8 show a ruler D, the construction of which is similar to that shown in Figs. 5 and 6 except for the fact that the rivets 39 which supplement the longitudinally extending grooves 3l similar to the grooves I5 in securing the edge strips 32 to the beveled edge portions 33 of the ruler body 35 have their heads embedded in the edge strips. The ruler E shown in Figs. 9l and 19 is similar to the ruler A shown in Figs. 1 and 2 except for the fact that the mechanical interlocks between the edge Ystrips 35 and the beveled edge portions 36 of the ruler body 3l formed by longitudinally extending grooves 38 similar to the grooves I5 shown in Fig. 2, are supplemented by projections 39 formed integral with the edge strips 35 adjacent the ends thereof, which projections extend into suitable apertures lil formed in the beveled edge portions of the rulez body. The apertures il@ are preferably counterbored or beveled from the underside of the ruler with the result that the construction resembles rivets formed integral with the edge strips 35. It is also tobe understood that the rivets or I3 consist of This construction positively holds the rivet-like fastening means shown in Figs. 5 to 10, 75

inclusive, may be employed throughout the entire length of the ruler rather than merely adjacent to the ends thereof, as shown in the drawings.

In the embodiments of the invention shown, the beveled edge portions of the ruler body extend or project underneath the edge strips and the edge strips project beyond the beveled edge portions and engage underneath the ends thereof to some extent. The aforesaid construction provides adequate support for the edge strips and the edge strips protect the under surface of the ruler body from excessive wear. The plastic edge strips are preferably applied to the ruler bodies by molding under heat and pressure and graduations can be simultaneously molded therein, if desired. During the molding operation, the plastic ows into the interlock grooves and apertures in the ruler body and becomes cemented thereto forming a strong mechanical connection between the edge strips and the ruler body proper.

From the foregoing description of the preferred embodimentsV of the invention, it will be apparent that the objects of the invention heretofore enumerated have been accomplished, and that a novel drafting ruler has been provided. While the preferred embodiments of the invention have been illustrated and described, I do not wish to be limited to the construction shown which may be varied within the scope of this invention. It is my intention to cover all variations, adaptations and uses thereof that come within the practice of those skilled in the art to which the invention relates, and I particularly point out and claim as my invention the following:

l. A composite drafting ruler comprising a ruler body extending from the upper surface to the lower surface of the ruler proper and having an outwardly tapering top beveled edge portion, said edge portion of said ruler body having a plurality of grooves therein opening into the upper beveled edge surface, and an edge strip on the top of said beveled edge portion and extend- L ing over t-he outer edge thereof formed from a plastic molded in position and mechanically interlocked with said beveled edge portion, said mechanical interlock comprising a plurality of longitudinally extending tongues and grooves on the edge portion of the ruler body and a plurality of longitudinally extending tongues and grooves on the edge strip interlocked with the tongues and grooves on the edge portion of the ruler body.

2. A composite drafting ruler comprising a metal ruler body extending from the upper surface to the lower surface of the ruler proper and having anV outwardly tapering top beveled edge portion, said edge portion of said ruler body having la plurality of Ygrooves therein opening into the upper beveled edge surface, and. an edge strip on the t'op of said beveled edge portion and extending over the outer edge thereof formed from a plastic molded in position and mechanically interlocked with said beveled edge portion, said mechanical interlock comprising a plurality of longitudinally extending tongues and grooves on the edge portion of the ruler body and a plurality of longitudinally extending tongues and grooves on the edge strip interlocked with the tongues and grooves on the edge portion of the ruler body.

3. A composite drafting ruler comprising a ruler body extending from the upper surface to the lower surface of the ruler proper and having an outwardly tapering top beveled edge portion, said edge portion of said ruler body having a plurality of grooves therein opening into the upper beveled edge surface, and an edge strip on the top of said beveled edge portion and extending over the outer edge thereof formed from a plastic molded in position and mechanically ind terlocked with said beveled edge portion, saidl mechanical interlock comprising a plurality of longitudinally extending tongues and undercut grooves on the edge portion of the ruler body and a plurality of longitudinally extending tongues and undercut grooves on the edge strip interlocked with the tongues and grooves on the edge portion of the ruler body.

4. A composite drafting ruler comprising a metal ruler body extending from the upper surface to the lower surface of the ruler proper and having an outwardly tapering top beveled edge portion provided with a plurality of longitudinally extending undercut grooves in the upper surface thereof, and an edge strip on the top of said beveled edge portion and extending over the outer edge thereof formed from a plastic molded in position and mechanically interlocked with said beveled edge portion by .the engagement of the material of said edge strip in said grooves; rsaid mechanical interlock comprising a plurality of longitudinally extending tongues and undercut grooves on the beveled edge portion of the ruler body interlocked with a plurality of cooperating undercut tongues and grooves on the edge strip.

5. A composite drafting ruler Icomprising a metal ruler body extending from the upper surface to the lower surface of the ruler proper and having an outwardly tapering top beveled edge portion provided with a plurality of longitudinally extending grooves and a plurality of transversely extending grooves in the upper surface thereof, and `an edge strip on the top of said beveled edge portion and extending over the outer edge thereof formed from a plastic molded in position and mechanically interlocked with said beveled edge portion by the engagement of the material of the edge strip in said grooves, said mechanical interlock comprising a plurality of longitudinally extending tongues and undercut grooves on the beveled edge portion of the ruler body interlocked with a plurality of cooperating longitudinally extending tongues and undercut grooves on the edge strip.

6. A composite drafting ruler comprising a metal ruler body extending from the upper surface to the lower surface of the ruler proper and having an outwardly tapering top beveled edge portion provided with a plurality of apertures extending therethrough and a plurality of longitudinally extending tongues and undercut grooves in the upper surface thereof, and an edge strip formed of a plastic molded in position and mechanically interlocked with said beveled edge portion by the engagement of the edge strip in said apertures and grooves, said mechanical interlock comprising a plurality of longitudinally extending tongues and undercut grooves on the beveled edge portion of the ruler body interlocked with a plurality of longitudinally extending tongues and undercut grooves on the edge strip.

7. A composite drafting ruler comprising a metal ruler body extending from the upper aperture surface to the lower surface of the ruler proper and having an outwardly tapering top beveled edge portion provided with a plurality of longitudinally extending tongues and undercut grooves in the upper surf-ace thereof, an edge strip' formed of a plastic molded in position and mechanically interlocked with said beveled edge portion by the engagement of the material of the edge strip in said grooves, said mechanical interlock comprising a plurality of longitudinally extending tongues and undercut grooves on the beveled edge portion of the ruler body interlocked with a plurality of longitudinally extending tongues and undercut grooves on the edge strip, and projections on said top beveled edge portion adjacent the ends of the ruler extending into said edge strip.

CHARLES H. LITTLE.

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