US2479511A - Drawing board - Google Patents

Description

Aug 4 J. c. PRATT Y 2,479,511

DRAWING BOARD Filed March 9, 1945 39 40 36 I I k I IINVENTOR 53 51 44 5 w ram apmw.

M 5E 1M H l5 ATTORNEY- Patented Aug. 16, 1949 UNITED STATES PATENT OFFICE "DRAWING BOARD ml: o. mu, Brooklyn Heights, is. 3y, Application March 9, 1945, Berta-1N0. 581,785

5 aims.

This invention relates to drawing boards, and more particularl to a dmwins board of the readi'ly portable tyne.

One object of the invention is to obviate the need of e considerablonumber and varied types of plane guiding instmments required Ior makin: a. drawing on the board.

Another object is to imfli ate the manipula tion of such guiding instruments on and their removal from the board.

Still another object is to enable a work-shoot to be qulcklysnd attentively secured to he board.

Other oblects will both port obvious and in part pointed out hereinafter.

In the drawings accompanying this specifics tion and in which similar reference numerals ire fer to similar parts,

Figure 1 is a plan view of c dramas board constructed in accordance with he practice. of the invention,

Figure 2 is an end view 01 the board illustrating more particularly one form of planeinstrument guide for the board,

Figure. 3 is a similar view howing a modified form of plane-instrument snide Figures 4 and 5 are transverse views taken through Figure 1 on the lines. 4-4 cod- 5-!i respectively! Figure 6 is a view similar to Figure .1. showing a modified form of the invention.

Figure 7 is an end view of board shown in Figure 6 showing a shittcble straight edge to: the board.

Figure 8 is an enlarged View of a portion o; the board and straight edge. shown inlFlgurs 6 illustrating more particularly the manner in which the straight edgemay be held in one 01 its limiting ositions.

Figure 9 is a transverse view taken through Figure 8 on the line 9. 8. and

Figure 10 is. a perspective view at a. detail.

Referring to the. drawing and at first more particularly to Figures 1 to 3 inclusive, Z0 designotes a drawing board of rectangular shape and 21 a plane workmpsurface having arran ed thereon c. work sheet 22-,

The board may he constructed of any suitable material possessing the quality of resistance to distortion under varyi g atmosph ric conditions. It should be sufllclently strong in maintain a m plane working surface under all conditions of use and is provided with means to serve as a straight edge for guiding plane instruments, as for exam ple a triangle 23 shown in dot and dash llnesin Figure 1. In one form such guide means consists of a strip 24 that seats against an edge of the board 20 and is fixedly secured thereto by suitable means, as for example nails 25.

The strip 24 is of less length then the board, its onds terminating at equal distances from adjacent corners of the board, and has on its up per side projections 26 that are spaced with respeot to each other and extend above the Work.- ing-suriace. In the form shown the width of the spaces between the projections 26 is coextensive with widths of the strip 25 and the projections 26 and the projections are of inverted V.-shape and their inner surfaces 2? confronting the working surface of the board are in alignment with each other and with the edge of the board 20 to serve as guiding surfaces for the triangle. The sloping surfaces 28 of the projections 26 decline at a low angle and preferably extend to points slightly be low the working surface so that the bottom sur faces 28 of the resulting depressions will lie below the working surface 2! and thus below the plane of movement of thetriangle.

Owing to this arrangement, the plane-instru merits will readily ride up over the projections 26 in inclined relation with the working surface, and may then be conveniently grasped for removing them from the board. In oder to further assure that the trian le may be readily ocmmed up over the projections the corners at the l junctures oi the sloping surfaces 28 and the guide surfaces 21 of said projections are removed. This moy be accomplished by formin eith r a beveled surface at this point or, as indicated more particularly in Figur 4, a round d, s fa e .30 of uch curvature that it will cause the triangle to veer from the working surface.

As will be readily understood: strips 24 may be armnged on each of the four edges of the board or, as shown in Fi ure 1, on adjacent sid s of. h board so that the guide urfaces 21 of asljaoent strips will lie in planes mutually perpendicular to each other.

As an alternative form of guide or straightedge for the. plane-instruments. he board so may be provided with s nplurclity of separate pla es 3| arranged at equally spaced intervals along an edge, or edges, of the board and secured thereto in the manner and with the means described in connection with the mode of securing the strips 24 to the board. The lower ends of the plates may lie flush with the under-surface 32 of the board and the opposite ends of the plates are in the form of projections 33, preferably of triangular shape, that extend above the working surface 2| and have their inner surfaces 34 in alignment with each other to serve as a straight edge for a plane-instrument.

The sloping surfaces 35 of the projections 33, like those of the projections 26, also incline at a low angle and their inner corners are also removed to provide thereon the rounded surfaces 39. The end members of a row of plates 3| are spaced a suitable distance from the adjacent corner of the board Eli, and on the upper surface of the board, between adjacent end plates or guide L strips, are beveled surfaces 36 that slope downwardly from the working surface to support the corner portions of the work-sheet.

Suitable means are provided for holding the work-sheet immovable on the board. In the form illustrated, such means consist of resilient holders or clamping devices 3'! that are initially in the form of a staple and have their legs 38 embedded in the edges of the board 20. The holders are of angular shape having their closed end or bar portions 39 overlying the legs 33 and in such relation thereto that when a bar 39 rests upon a beveled surface 38 the curved portions ll! at the juncture of the legs 38 with the body of a clamping device will be flexed in suitable degree to press the bar portion 35 firmly against the corners of the work-sheet. The spring portions ill may, as illustrated, be of U-shape, or in the form of loops, if desired.

In spring devices 3'! having two legs, as shown, said legs are driven diagonally into adjacent edges of the board and the bar 39 will then lie diagonally across the clamping surfaces 36. The bar 39 is, moreover, so positioned with respect to the base and the apex of a clamping surface 35 that it lies below the plane of the working surface and will, therefore, be well out of the path of movement of the drawing instruments on the worksheet.

In the form of the invention shown in Figures 6 to 10 inclusive, certain of the plane-instrrunent guiding strips are seated slidably upon edges of the board in order that all portions of the guiding strips may be removed out of the plane of the working surface. One form that such a strip may assume in practice, and designated 45, is similar to the strip 2%. It has the projections 26 on its upper edge and is of a length approximately equal to the distance between adjacent clamping surfaces 36. In a preferred form of the invention, the strip 4! is slidable in a plane normal to the working surface of the board and the distance of such movement is limited by pins 42 projecting from the edge of the board into slots 43 in the strip. The length of the slots determines the range of sliding movement of the strip, and their ends engage the pins 12 in the limiting positions of the strips. Thus, when the lower ends of the slots seat against the pins the projeotions will occupy their guiding positions, and when the opposite ends of the slots rest upon thepin the strip 4! will be in the fully depressed position wherein the projections 26 lie below the working surface and, therefore, out of the path of movement of the plane-instruments.

Convenient means are provided to hold the strip M in its limiting positions. To this end a plurality of spring clips 44, two in the present instance, are arranged at the edge of the board to press the strip 4! thereagainst. The spring clips have legs 45 to extend into the edge of the board and are bent to a suitable angle intermediate their ends to position the bar 46 for engagement with the side of the strip 4! and to flex the curved portion 4'! at such angle in the degree required to hold the strip in frictional engagement with the board.

In order to further assure against the inadvertent shifting of the strip, saidstrip is provided with a pair of grooves 48 in its side to interlockingly engage the bar 46. The grooves :28 are so spaced with respect to each other that when the strip is in the instrument-guiding position the bar 46 will lie in one groove, and when the strip is depressed below the plane of the Working surface the bar 45 will seat in the other groove 48.

In the form of spring member shown in Figures 6 to 9 inclusive, the spring portion 41 is shaped as a simple curve, or loop, but may be in the form of a helix 50, as shown more particularly in Figure 10.

As will be readily appreciated, shiftable strips 4i may be disposed on each of the four edges of a drawing board or only on certain edges and, if desired, one or more of the guide strips may be permanently attached to the board in the manner of the strip is at the upper edge of the board in Figure 6. The strips may, moreover, be of different form, as for example those designated 5!, in Figures 6 to 8 inclusive, and have plane upper edges 52 and beveled surfaces 53 sloping gradually downwardly from the edges 52 to the ends of the strips for tilting the plane-instruments. The strips 5| are also shiftable up and down at the edge of the board and are held firmly thereagainst by the spring members 44.

I claim:

l. A drawing board having a plane working surface, and a plurality of relatively spaced projections arranged against one edge of the drawing board and jutting above the working surface and having surfaces in alignment with each other to guide a drawing instrument, the width of the spaces between the projections being coextensive with the width of said projections.

2. A drawing board having a plane working surface, a plurality of projections arranged in spaced relation with each other along and acting against the edge of the board and having surfaces in alignment with each other to guide a drawing instrument, the width of the spaces between the project ons being coextensive with the width of said projections, and means for securing the projections to the edge of the drawing board.

3. A drawing board having a plane working surface, and a plurality of relatively spaced inverted vshaped projections at an edge of the board projecting above the working surface, and surfaces on the projections in alignment with a each other to guide a drawing instrument.

4. A drawing board having a plane working surface, a plurality of relatively spaced projections seating against one edge of the board and extending above the working surface, surfaces on the tops of the projections sloping downwardly in opposite directions, guide surfaces on the projections adjacent the working surface for guiding a drawing instrument, and cam surfaces on the projections at the junctures of the sloping surfaces with the guide surfaces.

6 5. A drawing board having a plane working REFERENCES CITED surface plurality of relatively spaced projec' The following references are of record in the tions seating against one edge of the board and me of this patent: extending above the working surface, guiding surfaces on the projections in alignment with 5 UNITED STATES PATENTS each other for guiding a drawing instrument on Number Name Dat the working surface, and beveled surfaces on the 1,314,060 Hagerstrom Aug. 26, 1919 projections at the junctures of guiding surfaces 1,686,980 Nuckols Oct. 9, 1923 with the upper surfaces of the projections to 1,759,989 Leaman May 27, 1930 guide a drawing instrument over the projections w 13491493 193 during the sliding of such instrument from the 13875382 9 Zlmmermann 8, 1935 working surface ll SBpt. 241, 2,060,355 Twomley Nov. 10, 1936 JACK PRATT 2,203,474 Stenquist June 4, 194

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