US3432929A - Spacer clip for a draftsman's straight edge - Google Patents

Description

March 18, 1969 J. L. YOU NGBLOOD 3,432,929

SPACER CLIP FOR A DRAFTSMAN'S STRAIGHT EDGE Filed Dec. 26, 1967 'Olflllllll "Illllllflll I N VENT 0R. L/A CK L. YOU/V651. 00D

A 7'70R/VEY nited States Patent Claims ABSTRACT OF THE DISCLOSURE A spacer clip for a draftsmans straight edge which is releasably mounted upon and extends under and transversely of the straight edge at any selected position, causing the undersurface of said straight edge to be spaced slightly above the drawing table surface to avoid rubbing thereof at points spaced from the clip.

Background of the invention This invention pertains to a spacing device for a darftsmans straight edge which is insertable between the upper surface of a drafting table and a selected part of the lower surface of the straight edge.

A continual problem experienced by draftsmen is the tendency for pencil drawn lines to become smeared as the straight edge is moved over the drafting paper during the course of drafting work. Even in making ink drawings there is a tendency for the drafting paper to become dirtied because of the straight edge being rubbed over the paper. This invention substantially eliminates the aforementioned difiiculties by the utilization of a spacer clip for the straight edge which can be positioned to contact the paper at a limited point only at any selected position, as between figures of the drawing.

Summary of the invention This invention comprises a narrow spacer clip having a base section adapted to underlie a straight edge from side to side thereof and having a top section carried by and overlapping said base portion which engages the top of said straight edge holding the base portion in engagement with the underside of said straight edge and terminating in a retainer engaging a side of the straight edge. By placing at least one and preferably two spacer clips about the straight edge at selected spaced positions, the underside of the straight edge is positioned above the table or drawing surface thereby preventing smearing of pencilled lines at parts spaced from the clips and generally improving the cleanliness of the drawing.

Accordingly, it is an object of this invention to provide a spacer between a draftsmans straight edge and the underlying drawing table for holding the straight edge adjacent to but out of contact with the drawing paper on the table.

It is also an object of this invention to provide a spacer which can be easily and rapidly installed upon and removed from a straight edge and which maintains any selected position thereon.

Still another object of this invention is to provide a spacer for a draftsmans straight edge which is formed of resilient material to releasably grip the straight edge and which is readily adjustable lengthwise along said straight edge.

Still another object of this invention is to provide a spacer for a draftsmans straight edge which is of simple and economic construction.

Other objects of this invention will become apparent upon reading the inventions description.

Brief description of the drawing FIG. 1 is a perspective view of a drafting board with an adjustable guided straight edge, showing the spacer clips of this invention mounted upon the straight edge.

FIG. 2 is an enlarged perspective view of one form of the spacer clip.

FIG. 3 is a fragmentary detail sectional view taken along line 33 of FIG. 1 showing the spacer clip mounted around the straight edge.

FIG. 4 is a top plan view of the spacer clip of FIG. 2.

FIG. 5 is a fragmentary longitudinal detail sectional view of the leading end portion of the spacer clip base.

FIG. 6 is a fragmentary longitudinal detail sectional view showing a modification of the leading end portion of the spacer clip base.

Brief description 07 the preferred embodiment The preferred embodiment illustrated is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is chosen and described in order to best explain the principles of the invention and its application and practical use, to thereby enable others skilled in the art to best utilize the invention.

The straight edge spacer clip is best shown in FIG. 2. Clip 10 is preferably formed from a strip of resilient sheet metal or strip of plastic. The clip has a substantially flat base portion 12 adapted to underlie the underside 14 of a straight edge 16 and thereby ride upon the upper surface of a drafting table 18. Straight edge 16 is a standard draftsmans tool movably mounted at its end portions to the drafting table and movable sidewise across the surface of the drafting table in selected orientation to the edges of the table. The leading or free end portion 20 of base 12 is preferably beveled at its bottom as shown in FIG. 5. Alternatively the free end portion of base 12 may be slightly upwardly inclined at 20 as shown in FIG. 6. In addition, the free end portion may also be rounded. The arrangement is designed to avoid occurrence of burrs and sharp edges or corners and thus prevent the clip 10 from scratching or marring the table or paper surface over which it rides as the straight edge is moved during use.

An inclined section 24 preferably extends upwardly from a return bent part 22 projecting upwardly from base 12. Integrally connected to inclined section 24 is a top section 26 preferably substantially parallel to base 12 and generally overlying base 12 in a spaced relationship preferably slightly less than the thickness of the straight edge. Section 26 terminates in a downwardly projecting retainer such as a downturned inwardly inclined hook portion 28 having a outwardly turned marginal end portion 30 spaced above the base 12.

Clip 10 is formed of a size and shape correlated to the size and cross sectional shape of the straight edge with which it is to be used. Thus for a straight edge 16 having a longitudinal top rib 34 and opposite edge parts 32, 35, as shown in FIG. 3, the return bend 22 of clip 10 is formed to fit snugly upon and extend around straight edge part 32 when its leading edge 20 terminates spaced inwardly of the upper drafting edge part 35 of the straight edge. The thickness of base 12 of clip 10 and, in addition with respect to the modification of FIG. 6, the extent of inclination of the margin of leading edge 20 must be less than the thickness of a triangle or other drafting tool which abuts the edge part 35 of the straight edge during drafting. The spacing of hook 28 from return bend 22 is selected to provide a snug fit and anchorage of hook 28 at the shoulder part 36 of rib 34 of the straight edge when bend 22 engages edge part 32.

The clip 10 may be constructed of any flexible material such as spring steel or plastic, and its base 12 may be coated at least at its undersurface with an anti-friction material such as a tetrafluoroethylene polymer, thereby reducing the friction between the clip and the drafting table or paper surface.

The resilience of the clip permits flexing thereof for rapid and simple application and removal thereof. While a single clip 10 may be utilized, it is preferable to use a pair of clips positioned on either side of the drawing paper 38 as illustrated in FIG. 1, or, when large drawings or tracings are involved, positioned astraddle the particular view or figure being drawn upon the sheet, Each clip 10 is adapted to be slid lengthwise along the straight edge and thus readily adjusted to a selected position without having to be removed from the straight edge, but retains by a spring grip action any position in which it is set. Since the clip 10 extends around only edge part 32 of the straight edge 16, exposing the remaining edge 35, drawing instruments such as pencils, pens and triangles may be moved along the straight edge part 35 without being obstructed by the clip 10.

It will be understood the invention is not to be limited to the details herein given.

What I claim is:

1. A spacer clip for a draftsmans straight edge movable over a drawing surface and having opposed edge parts and an arrow top rib comprising:

a thin resilient member of narrow width having a flat base portion underlying said straight edge and of a length less than the spacing of said opposed edge parts,

a top portion return bent from said base portion and extending around one edge part and overlying said rib, and

a retainer downwardly projecting from the end of the top portion to engage the portion of said rib remote from the edge part engaged by said top portion,

said member resiliently engaging and clamping said straight edge to maintain any selected position lengthwise thereon with said base portion spacing said straight edge slightly above said drawing surface.

2. The spacer clip of claim 1, wherein said base portion at its free end is of a rounded configuration.

3. The spacer clip of claim 1, wherein said base portion is upwardly inclined at the margin of its free end.

4. The spacer clip of claim 1, wherein said base portion at its free end is beveled.

5. The spacer clip of claim 1, wherein the underside of said base portion engaging the drawing surface is of a substantially friction free composition.

References Cited UNITED STATES PATENTS 1,249,049 12/1917 Eifel 33-107 1,498,994 6/1924 Borsuk et al 33104 1,806,422 5/ 1931 Shaen 235-702 2,246,491 6/1941 Abell 33107 2,411,529 11/ 1946 Dohrwardt et al 33107 3,178,826 4/1965 Aisen 33107 3,251,131 5/1966 Justis 33-80 HARRY N. HAROIAN, Primary Examiner.

US. Cl. X.R. 3380

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