US3638318A

US3638318A - Drafting apparatus and method of use thereof

Info

Publication number: US3638318A
Application number: US25988A
Authority: US
Inventors: Thomas R Herrmann
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-04-15
Filing date: 1970-04-06
Publication date: 1972-02-01
Anticipated expiration: 1989-02-01

Abstract

A curved drawing board and an associatedly curved rectangular parallel ruling slider mounted thereon. The rectangular parallel ruling slider including glides extending from each corner and making substantially point contact with the curved drawing board such that when all glides are in contact with the drawing board the edges of said parallel ruling slider assume a constant spatial relationship with the surface of said board such that lines drawn on a sheet of paper on said board along these edges are either horizontal or vertical. A method of drawing horizontal or vertical lines by positioning a rectangular frame on a curved drawing board and using the edges of said frame as a guide for drawing said lines.

Description

United States Patent Herrmann [54] DRAFTING APPARATUS AND METHOD OF USE THEREOF [72] Inventor: Thomas R. Herrmann, 5256 46th S.W.,

Seattle, Wash. 981 16 [22] Filed: Apr. 6, 1970 [21] Appl.No.: 25,988

[52] US. Cl ..33/75, 33/76 [51] Int. Cl. ..A47b 27/00 [58] Field of Search ..3l2/231; 33/1 AA, 75, 79,108, 33/ 184.5

[56] References Cited UNITED STATES PATENTS 767,717 8/1904 Hill et a1 ..33/1 AA 2,907,620 10/1959 Van Luik, Jr. ..33/1 AA 51 Feb. 1, 1972 Primary Examiner-Leonard Forman Assistant Examiner-Charles E. Phillips Attorney-Graybeal, Cole & Barnard [5 7] ABSTRACT A curved drawing board and an associatedly curved rectangular parallel ruling slider mounted thereon. The rectangular parallel ruling slider including glides extending from each comer and making substantially point contact with the curved drawing board such that when all glides are in contact with the drawing board the edges of said parallel ruling slider assume a constant spatial relationship with the surface of said board such that lines drawn on a sheet of paper on said board along these edges are either horizontal or vertical.

A method of drawing horizontal or vertical lines by .positioning a rectangular frame on a curved drawing board and using the edges of said frame as a guide for drawing said lines.

19 Claims, 18 Drawing Figures PATENTEDHBI I972 3.638.318

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11 52 ATTORNEYS DRAFTING APPARATUS AND METHOD OF USE I THEREOF BACKGROUND OF THE INV ENTION l. Field of the Invention i This invention relates in general to drafting equipment, and in particular, to drafting tables and devices used in conjunction therewith to draw horizontal, vertical and angular lines on sheets of paper mounted on said tables.

2. Description of the Prior Art 1 The prior art in this field includes conventional flat rectangular drawing boardsfand drafting equipment used therewith for drawing parallel, perpendicular and angular linessuch as T-squares, triangles, parallel ruling straight edgesand drafting machines. Drawing boards of the prior art are usually made of soft woods such as White Pine or Basswood which is at least three-quarters of an inch in thickness. Planar drawing boards made of other substances are also known, the top surfaces thereof often being coated with a plastic or composition material. The equipment generally used in conjunction with these planar drawing boards include T-squares which comprise a straight edge securely anchored to a head such that the straight edge and head form an angle of 90. The head is adapted to be mounted on the edge of the drawing board such that movement of the head along the edge of the drawing board allows parallel horizontal lines to be drawn along the straight edge which extends across the surface of the drawing board. A triangle must be used in conjunction with the T- square to draw vertical and angular lines. Parallel ruling straight edges are similar to the T-square in providing a straight edge mounted horizontally across the drawing board, but the parallel ruling straight edge is slidably connected to the drawing board at both of its ends. Triangles must also be used to draw vertical and angular lines. Drafting machines which include two arm portions joined at a pivotal elbow may be used to draw horizontal, vertical and angular lines, but the pivoting elbow often extends outwardly from the drafting table and may interfere with an adjacent wall or work area.

BRIEF SUMMARY OF THE INVENTION The present invention provides a means for drawing horizontal, vertical and angular lines on a sheet of paper comprising a curved drawing board having a rectangular frame, with projections extending from the corners thereof, mounted thereon. The interaction of the curved drawing board and the rectangular frame are such that when the corner projections of the frame are all seated firmly on the curved surface the top and bottom edges of the frame may be used to draw horizontal lines on a piece of paper disposed between the curved drawing board and the frame, and the side edges of the frame may be used to draw vertical lines.

It is an object of the present invention, therefore, to provide drafting apparatus which may' be used to draw horizontal and vertical lines at any point on the surface of a drawing board.

It is a further object of the present invention to provide drafting apparatus whereby vertical and horizontal lines may be drawn without the aid of a T-square, parallel ruling straight edge, or conventional drafting machine. I

Still another object of the present invention is to provide drafting apparatus peculiarly adapted for use for drawings having a greater than average length.

A further object is to provide drafting apparatus for drawing.

, junction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of one typical embodiment of the present invention, including a concavely curved drawing board and aparallel ruling slider disposed thereon.

vertical and horizontal lines one element which isfrq yil slidable on the surface of a curved drawing board. 1

An additional object is to provide drafting apparatu wherein the slidable element includes glide means which tend to position the edges of the slidable element along horizontal and vertical lines.

One more object is to provide drafting apparatus wherein adjustment of the glide means allows the edges of the slidable element to be aligned with horizontal or vertical lines on a premounted sheet of paper on a drafting table.

FIG. 2 is aside elevation view of the drafting apparatus of FIG. I.

FIG. 3 is a perspective view of another typical embodiment of the present invention, including a convexly curved drawing board and a parallel ruling slider mounted thereon.

FIG. 4 is a side elevation view of the drafting apparatus of FIG. 3.

FIG. 5 is a partial perspective view of the drawing surface of a typical embodiment of the present invention, including the parallel ruling slider shown in dotted line translated across the surface of the drawing board.

FIG. 6 is a partial sectional view taken along line 66 of FIG. 5.

FIG. 7 is a partial sectional view taken along line 7-7 in FIG. 5.

FIG. 8 is a plan view of a typical embodiment of the parallel ruling slider of the present invention, including a substantially open central area.

FIG. 9 is a plan view of another typical embodiment of a parallel ruling slider of the present invention, including a template.

FIG. 10 is still another typical embodiment of a parallel ruling slider of the present invention, including a centrally disposed protractor.

FIG. 11 is a partial sectional view taken along lines Il-1I in FIG. 10.

FIG. 12 is a partial elevation view showing one typical embodiment of a glide means, including an axially mounted wheel adapted to run on its side.

FIG. 13 is a partial elevation view of another embodiment of a glide means.

FIG. 14 is a partial elevation view of another typical embodiment of a glide means, including an axially mounted wheel running on one edge.

FIG. 15 is a partial elevation view of another typical embodiment of a glide means, including a wheel mounted on an eccentric axle.

FIG. I6 is a partial elevation view of another typical embodiment of a glide means, including a ball and ball clutch.

FIG. 17 is a sectional elevation view of the embodiment of FIG. 16 rotated FIG. 18 is a schematic diagram showing glide rotation in one embodiment of the present invention.

DETAILED DESCRIPTION Referring now to FIGS. I and 2, an embodiment 10 of a drafting apparatus of the present invention is shown including a drawing board 12 curved about one axis and having a parallel ruling slider 14 seated on its tup surface. In the disclosed preferred embodiment, the curvature of the drawing board corresponds to the curvature of a segment of the perimeter of a circle having a 60-inch radius. Other curvatures between 30- and 72-inch radius may also be used with the only requirements being that the curvature be large enough to provide the unique relation described herein between slider 14 and the drawing board 12, and small enough that a draftsman may conveniently draw thereon.

The parallel ruling slider, which will be described in greater detail hereafter, may be a relatively rigid rectangle having a curvature along its width equal to the curvature of the drawing board.

FIGS. 3 and 4 disclose another embodiment of the drafting apparatus of the present invention comprising a convex drawing board 16 and a parallel ruling slider 18 having a corresponding convex curvature along its width. Drawing board supports 20 in FIGS. 1 and 2 and 22 in FIGS. 3 and 4 as illustrated, include

legs

24 and 26 and drawing board supports 28 and 30. Support 28 includes a substantially concave upper portion which conforms to the curvature of drawing board 12, while support 30 includes a substantially convex upper portion which conforms to the curvature of board 16. It is understood that numerous other suitable drawing board supports may be substituted for those disclosed herein, including supports mounted on desks, cabinets, and walls. Although not disclosed, a rotatable support is also contemplated whereby a single drawing board may be used as either a concave or convex drawing board depending upon its rotation. The drawing board support should be such that the drawing surface may be tilted upwardly away from the draftsman at an angle of between and but this angle of tilt may be varied according to the preferences of the user and the requirements of the drafting job.

As is best shown with reference to FIGS. 6 and 7, the drawing board 12 may include a honeycomb inner core 32 sandwiched between flexible top and bottom covering players 34.

FIG. 5 discloses a more detailed view of the parallel ruling slider 14 mounted on the curved drawing surface 12. Slider 14 is preferably constructed of clear plastic which is injection molded and then heated and bent into a curve corresponding to that of the drawing board. It is understood that the slider could also be molded initially with a curved surface. Slider 14 includes beveled

edges

36 and 38 along its width and length. These beveled edges may include measuring scales (not shown), and in various embodiments may include architects scales, mechanical engineering scales, civil engineering scales, metric scales or combinations of these scales. Openings 40 are located in the central portion of the slider 14 to allow easier marking on a sheet of paper 42 mounted on the drawing board. Openings 40 also include beveled edges 44 which may be used as guides when drawing vertical or horizontal lines. Hand grip 46 is mounted on central rib 48 to allow for gripping of the slider when it is to be moved transversely on the drawing board during use. It is thus seen that slider 14 comprises a simple rectangular frame having an arcuate curvature along beveled edges 36.

Slider 14 includes glide means 50 disposed near each of its corners, and as will be seen by reference to FIGS. 6 and 7, the glides at various corners of the slider may vary in configuration. In FIG. 6, glide 52 comprises a simple metal or plastic plug with a hemispherical bottom mounted in a hole 54 extending through the corner of the slider. Plug 52 may be glued in hole 54, or fixedly held therein by any other suitable means. Glide 56 is an adjustable skid screw having a hemispherical bottom portion, which is adjustably mounted in internally threaded bushing 58. Bushing 58 is, in turn, fixedly seated in hole 60 disposed near a corner of slider 14. It is thus seen, that the extent of the projection of skid screw 56 below the slider may be adjusted by turning skid screw 56 within bushing 58. Skid screw 56 may be constructed of various materials including wood or plastic, but it is preferred that it be made of hardened steel. It has been found that a %-l6thd. screw is a convenient size. As seen in FIG. 8, slider 14 includes two plugs 52 mounted at the corners along one longitudinal edge 38, and adjustable skid screws 56 mounted at the corners along the opposite longitudinal edge. As will be discussed more completely hereafter with reference to the operation of the instant apparatus, the raising or lowering of skid screws 56 allows adjustment of the slider for parallelism with respect to the curved surface 12. Raising or lowering of screws 56 adjust the angle which the

beveled edges

36 and 38 make with respect to vertical and horizontal lines already drawn on a sheet of paper which is mounted on the curved drawing surface. Various other glide configurations will be discussed hereafter with reference to FIGS. 12-17.

Referring now to FIG. 9, another embodiment of slider 14 is shown wherein a template 62 is disposed on the inner surface thereof. As illustrated, the template includes line openings 64 and 66 running towards each other at the commonly used angles 15, 30, 45 and 60. Various circles of different radius and triangles, squares, hexagons and parallelograms of different area are also included on the template. It is understood, however, that other openings of various size, shape or angle may be added thereto, or other templates having different patterns may be associated with other sliders. For example, different sets of templates may be provided for machine designers, architects or commercial artists which are best suited to their varying needs.

FIGS. 10 and 11 disclose a slider 14 including a centrally located rotatable protractor 68 mounted thereon. The protractor includes a centrally located handle 70 which is mounted on rotatable portion 72. Rotatable portion 72 is seated on steps 74, and held in place by fixed azimuth 76 which is mounted on the slider 14 and extends in part over the circular edge of rotatable member 72. Azimuth 76 is marked to define the 360 of a circle, and thus the rotation of member 72 allows the measurement or laying out of angles on a sheet of paper on the drawing board 12. To further assist in this measurement or laying out, internal scales 78 are also provided.

FIGS. 12-17 disclose various other glide embodiments which may be substituted for skid screws 56 of plugs 52. FIG. 12 discloses rotatable wheel 80 having centrally located axle 82 extending normally therefrom and connecting the wheel to threaded setscrew 84. Setscrew 84 cooperates with internally threaded fixed bushing 86 to allow wheel 80 to be raised or lowered into or out of the recess 88 in slider 14.

FIG. 13 discloses the glide means of FIG. 12 mounted such that wheel 80 is disposed in recess 90 to meet drawing board surface 12 at a substantially greater angle than that shown in FIG. 12.

FIG. 14 discloses a glide means including flat surfaced roller 92 axially mounted on rod 94 which is in turn integrally connected to adjustable setscrew 96. Rotation of setscrew 96 causes wheel 92 to move transversely in recess 98, and the transverse movement of this wheel taken in conjunction with the curved lower surface of slider 14 causes wheel 92 to project varying distances below slider 14.

FIG. 15 discloses a curved surface roller 100 normally mounted on eccentric axle 102 which includes threaded head 104 mounted in threaded hole 106. Rotation of threaded head 104 and its associated eccentric-axle causes wheel 100 to move into or out of recess 108 thereby varying the amount which the wheel extends below the lower surface of the slider.

FIGS. 16 and 17 disclose still another glide means comprising spherical roller 110 mounted in bracket 112. Bracket 112 includes threaded top hole 114 which is adapted to receive threaded screwcap 116. Screwcap 116 includes spherical recessed point 118 which bears upon roller 110 such that the lower portion of the roller extends below the lower surface of slider 14. The amount of this extension may be varied by rotation of threaded screwcap 116. As is best shown in FIG. 17, this embodiment also includes conventional ball clutch 120. The ball clutch is mounted in bracket 112 such that roller 110 is biased against rotation in one direction while it is free to rotate in all other directions.

In one embodiment of the slider of the present invention, pairs of glide means, such as those disclosed in FIGS. 16 and 17, which are biased against rotation in opposite directions are mounted on the slider 14 near the corners adjacent its short edgesFIG. [8 schematically illustrates the direction of rotation of these pairs of glide means when slider 14 is moved in the direction indicated by arrow 122. Glide means 124 on the leading edge of the slider are adapted to rotate freely in the direction of arrow 122, while glide means 126 are biased against rotation in this direction. Thus, movement of the slider in the direction of arrow 122 causes glide means 126 to slide rather than roll, thereby imparting a stabilizing effect to the slider such that the slider tends to assume a position wherein its long edges are horizontal and its short edges are vertical with respect to a sheet of paper mounted on the curved drawing board. It will be understood .that movement of the slider in a direction opposite arrow [22 causes glide means 124 to slide while glide means 126 rotate freely, such that a stabilizing effect is again imparted to the slider.

An additional embodiment is also contemplated wherein the glide means are free to rotate in only a single direction, with opposed pairs of glide means biased to rotate oppositely. The operation of this embodiment would provide the stabilizing effect discussed above, while additionally providing that all four glide means would slide, rather than rotate whenever the slider was moved in a direction other than that defined by arrow 122 or opposite thereto.

Referring now to FIG. 5, the use and operation of one embodiment of the instant invention will be described. A blank sheet of paper 42 is first conventionally mounted by means of tape or pins on the top surface of curved drawing board 12. Slider 14 is then placed on top of the sheet of paper such that glides 50 are all in firm contact therewith. The relationship between the glides on the curved slider and the curved drawing board itself is such that when all four glides are in contact with the paper the beveled edges of the slider are disposed such that lines drawn therealong will be either horizontal or vertical on the sheet of paper depending upon the edge used. When it is desired to draw another horizontal or vertical line at a different point on the mounted sheet of paper, the slider may simply be moved across the surface of the curved drawing board, repositioned such that all four glides are in firm contact with the curved drawing board, and additional lines drawn using the beveled edges of the slider as guides. In FIG. 5, the slider 14 is shown in full line at one point on the surface of a sheet of paper 42, and at a second point on the surface in dotted line. Lines drawn along edges 38 in both of these positions will be parallel to each other, as will lines drawn along edges 36.

If it is desired to use the disclosed drafting apparatus in conjunction with a partially completed drawing, the partially completed drawing is first conventionally mounted on the curved drawing board such that the horizontal lines on the drawing are substantially horizontal when viewed by the draftsman. A horizontal or vertical line on the partially completed drawing is then chosen as a reference line, and the appropriate horizontal or vertical edge of the slider is aligned therewith. In most instances it will be found upon aligning the edge of the slider and the reference line that the corner mounted glides on the slider are not all in firm contact with the surface of the drawing mounted on the curved drawing board. In this situation, adjustable glide means 50 should be manipulated until all four glide means are firmly seated, and in this manner the slider is adjusted for parallelism with respect to the reference line. All lines drawn along the edges of the slider at any other point on the surface of the drawing board will now be either parallel or perpendicular to the reference line depending upon the edge of the slider used as a guide. Once the slider is adjusted for parallelism, its use is the same as has been described above with regard to drawing on a fresh sheet of paper. When it is desired to make angle lines on the drawing, triangles may be used in conjunction with the slider as is standard drafting procedure with a T-square, or a parallel ruling slider including a template such as that shown in FIG. 9 or a protractor as shown in FIG. 10, which has been properly adjusted for parallelism, may be used.

While the present invention has been described above with respect to various embodiments, it is also contemplated that a drawing board having an adjustable curvature consisting of a plurality of laminated sheets may also be provided. Additionally, it is understood that a planar parallel ruling slider, rather than one curved to conform to the drawing board may also be used, particularly in conjunction with the concave drawing board embodiment.

The invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present embodiments are therefore to be con sidered in all respects as illustrative and not restrictive. the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore to be embraced therein.

What is claimed is:

l. A drafting apparatus for marking a sheet of paper comprising a cylindrically curved drawing board and a rectangular parallel ruling slider having substantial cross-sectional stiffness, said slider having glide means mounted near each corner whereby said slider rests upon said sheet of paper on said curved drawing board such that when all of said glide means are in contact with said paper the edges of said slider define horizontal and vertical lines on said paper.

2. The drafting apparatus of claim I wherein the cylindrically curved drawing board defining a portion of the surface of a right circular cylinder having a radius of curvature between 30 and 72 inches.

3. The drafting apparatus of claim 1 wherein the curved drawing board comprises a flexible core structure having a flexible drawing surface mounted on the top side thereof.

4. The drafting apparatus of claim I wherein the drawing board is concavely curved along its width.

5. The drafting apparatus of claim I wherein the glide means include roller means biased to rotate freely in only one direction.

6. A drafting apparatus for marking a sheet of paper comprising a rectangular drawing board cylindrically concavely curved and a rectangular parallel ruling slider of substantial cross-sectional stiffness having glide means mounted near each corner, said slider adapted to rest upon said sheet of paper on said concavely curved board such that when all of said glide means are in contact with said paper the edges of said slider define horizontal and vertical lines on said paper.

7. A drafting apparatus the combination including a rectangular cylindrically curved drawing board and a correspondingly curved rectangular parallel ruling slider of substantial stiffness having glide means disposed near each corner of said parallel ruling slider, said glide means adapted to make substantially point contact with said drawing board such that when all of said glide means are in contact with said board the edges of said slider are parallel to the corresponding edges of said board.

8. The drafting apparatus of claim 7 wherein the glide means extend from said rectangular parallel ruling slider, the amount of said extension being adjustable.

9. The drafting apparatus of claim 7 wherein the glide means include rollers adapted to rotate freely in only one direction.

10. The drafting apparatus of claim 7 wherein the glide means include a spherical roller and an associated ball clutch such that said spherical roller is biased against rotation in one direction.

11. The drafting apparatus of claim 7 wherein the rectangular parallel ruling slider includes a beveled outer edge, said edge including a scale.

12. The drafting apparatus of claim 7 wherein the rectangular parallel ruling slider includes a protractor.

13. The drafting apparatus of claim 7 wherein the rectangular parallel ruling slider includes a template.

14. The drafting apparatus of claim 7 wherein the rectangu- -lar parallel ruling slider comprises an external frame and a paper on a cylindrically curved drawing surface. placing a substantially stiff rectangular frame on said paper at a first position, positioning said frame so that it will not rock when downward pressure is applied to any portion thereof, drawing a line on said paper along one edge of said frame, moving but not rotating said frame on said paper to a second position, positioning said frame such that it will not rock when downward pressure is applied to any portion thereof, and drawing a second line along the same edge of said frame.

18. A drafting method for drawing parallel lines comprising the steps of mounting a sheet of paper on a cylindrically concavely curved surface, placing a correspondingly curved substantially stiff rectangular frame having projections extending from each corner at a first point on said paper, positioning said frame so that said projections all contact said paper, drawing a line on said paper along one edge of said frame, moving but not rotating said frame on said paper to a second point. positioning said frame so that its projections all contact said paper, and drawing a line on said paper along the same edge of said frame.

[9. The drafting method of claim 18 wherein perpendicular lines are drawn by drawing lines on said paper along adjacent edges of said frame before and after moving said frame.

Claims

1. A drafting apparatus for marking a sheet of paper comprising a cylindrically curved drawing board and a rectangular parallel ruling slider having substantial cross-sectional stiffness, said slider having glide means mounted near each corner whereby said slider rests upon said sheet of paper on said curved drawing board such that when all of said glide means are in contact with said paper the edges of said slider define horizontal and vertical lines on said paper.

2. The drafting apparatus of claim 1 wherein the cylindrically curved drawing board defining a portion of the surface of a right circular cylinder having a radius of curvature between 30 and 72 inches.

4. The drafting apparatus of claim 1 wherein the drawing board is concavely curved along its width.

5. The drafting apparatus of claim 1 wherein the glide means include roller means biased to rotate freely in only one direction.

14. The drafting apparatus of claim 7 wherein the rectangular parallel ruling slider comprises an external frame and a substantially open central area.

15. The drafting apparatus of claim 7 wherein the rectangular parallel ruling slider is substantially planar.

16. The drafting apparatus of claim 7 wherein the rectangular parallel ruling slider is composed of a flexible plastic material.

17. A drafting method for drawing horizontal or vertical parallel lines comprising the steps of mounting a sheet of paper on a cylindrically curved drawing surface, placing a substantially stiff rectangular frame on said paper at a first position, positioning said frame so that it will not rock when downward pressure is applied to any portion thereof, drawing a line on said paper along one edge of said frame, moving but not rotating said frame on said paper to a second position, positioning said frame such that it will not rock when downward pressure is applied to any portion thereof, and drawing a second line along the same edge of said frame.

18. A drafting method for drawing parallel lines comprising the steps of mounting a sheet of paper on a cylindrically concavely curved surface, placing a correspondingly curved substantially stiff rectangular frame having projections extending from each corner at a first point on said paper, positioning said frame so that said projections all contact said paper, drawing a line on said paper along one edge of said frame, moving but not rotating said frame on said paper to a second point, positioning said frame so that its projections all contact said paper, and drawing a line on said paper along the same edge of said frame.

19. The drafting method of claim 18 wherein perpendicular lines are drawn by drawing lines on said paper along adjacent edges of said frame before and after moving said frame.