US2826816A - Selective scale drawing instrument - Google Patents

Description

March 18, 1958 w. MAJOR 2,826,816

SELECTIVE SCALE DRAWING INSTRUMENT 2 Sheets-Sheet 1 Filed July 25, 1955 William 8. Major IN VEN TOR.

2 Sheets-Sheet 2 W. B. MAJOR SELECTIVE SCALE DRAWING INSTRUMENT March 18, 1958 Filed July 25, 1955 William B. Major INVENTOR.

United States Patent 2,826,816 SELECTIVE SCALE DRAWING INSTRUMENT William B. Major, Burbank, Calif. Application July 25, 1955, Serial No. 523,996 3 Claims. (Cl. 33-107) This invention relates to improvements in multiscale instruments especially useful in various types of drafting work.

An object of this inventon is to provide a multiscale instrument which is compact, thin and very easily used in drafting work.

A more specific object of the invention is to provide a multiscale instrument which includes a housing having I entrances along the side edges thereof, this housing being arcuate in cross-section and containing two or more blades,

each blade having scale indicia thereon and means opergreat number of indicia crowded in a small space is' avoided.

These together with other objects and advantages which will become subsequently apperent reside in the details of construction and operation as more fully hereinafter idescribed and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a perspective View of one form of the invention;

Figure 2 is a longitudinal sectional view taken on the line 22 of Figure 1 and in the direction of the arrows;

Figure 3 is a transverse sectional view taken on the line 3-3 of Figure 2 and in the direction of the arrows;

Figure 4 is an exploded perspective view of the block used to move the blade to which it is connected in and out of the housing together with a detent whose purpose is to lock the blade in the selected position;

Figure 5 is a top view of a suggested blade;

Figure 6 is a top view of another suggested blade having different indicia thereon and provided with one less slot than Figure 5;

Figure 7 is a top view of further blade with other indicia on it and one less slot, the blades of Figures 5, 6

and 7 being adapted to rest upon each other in nested fashion to form the group of blades shown in Figure 2-,

Figure 8 is a top view of the locking means and means of extending the blades together with suggested indicia thereon to indicate the scale which is to be extended into view when a particular block is actuated; and

Figure 9 is a fragmentary top view of a modified locking device for one of the blades.

As shown best in Figures 1-3, the multiscale drafting instrument or rule 10 has a specially designed housing including an upper plate 12 and a lower plate 14, each of which is arcuate in cross-section. Plates 12 and 14 are thin and elongated, and are held spaced from each the housing will come In this way, the

, from its central rest 2,8231% Patented Mar. 18, 1953 other by end walls formed by spacer blocks 16 and 18. In this way, elongated entrances 19 and 20 are formed along the edges of the instrument 10.

Two or more blades having scales thereon may be provided within the housing. For illustrative purposes only, three blades 22, 23 and 24 respectively are used in the make-up of instrument 10. They are adapted to be nested with each other with the blade 22 on the bottom, the blade 23 in the middle and theblade 24 on the top. Various indicia may be placed on the edges of the blades in order to form scales of various types. 7

In blade 22, there are a pair of slots 25 and 26. Similar slots 27 and 28 are formed in blade 23, while other slots 29 and 30 are formed in blade 24. When the blades are nested, all of the slots on the left sides of the blades are aligned (Figure 2) and all of the slots on the right side of the blades are aligned. Guide block 32 which is secured to the plate 14, is fitted in slots 25, 27 and 29. An identical guide 34 also secured to plate 14 is disposed in aligned slots 26, 23 and 30. Guide means 32 and 34 function to prevent the blades from being separated from the housing, and function in a guiding way to make certain that the blades enter, pass through or are withdrawn through entrances 19 and 20 smoothly and Without jammmg.

Means for extending a selective blade through a selected entrance 19 or 20 are attached to the various blades. For the top blade 24, there is a block 36 fixed to it at approximately its center, and this block may have it upper surface knurled, as at 38. Block 36 extends through a slot 40 in plate 12. A detentj42 is carried by the block 36 and coacts with the notches 44, 45 and 46 formed in an upstanding rib on plate 12 adjacent one longitudinal edge of slot 41). Suitable markings may be placed on the plate 12 adjacent slot 40 to indicate which scale will be extended when the block 36 is pushed from its retracted position with detent 42 in notch 45 either to the notch 44 or toward the notch 46.

Block 48 is fixed to the top surface of blade 23 and it is adapted to be actuated to push the blade 23 through either of the entrances 19 or 20 and to withdraw the blade into the housing. In order to be accessible from the exterior of the housing, the block 48 is passed through an opening Si) in the blade 24 prior to being passed through the slot in the plate 12 adjacent which a looking mechanism identical to that described in connection wtih block 36 is provided.

A block 52 which is fixed to the top surface of blade 22 and which passes through slots 53 and 5d of blades 23 and 24, respectively, is used for actuating the blade 22. Block 52 has a locking detent which coacts with locking notches along the side of a slide in top plate 12 for the same purposes as described in connection with the blocks 48 and 36 of blades 23 and 24.

As an alternative for the detents 4'2 and locking notches such as those at 44, 45 and te, a block 55} may be used (Figure 9), this block having a generally pointed end 69 removably disposed in the series of Wells 61, 62 and 63 formed in a spring bar 64. This spring bar is secured to an upstanding rib 65 on the top plate of the housing and extends slightly over the slot within which the block 555 is operable. in use of either structure, however, the user of the multiscale rule selects the scale that he desires and then pushes the appropriate block position to one end of the slot within which it is operable the other, depending on whether he desires the scale to be extended through the entrance 19 or the entrance in the housing. When extended, the locking means will hold the scale in the extended position so that it will not move or wiggle with respect to the housing.

In use of the multiscale rule, it is simply placed on the drawing surface. in this regard, the lower plate 14 has its longitudinal edges 63 and 70 beveled to compensate for the curvature of plate 14 in having plate 14 rest firmly flush upon the drawing surface. The longitudinal edges of each blade, for example, edges 72 and 74 of blade 22, are similarly beveled so that when the blade 22 is extended from the housing, it also fits flush against the drawing surface. The curvature of the housing and blades (Figure 3) together with this bevel makes it possible to have the blades extended outwardly of the housing and fit firmly against the plane drawing surface.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the inven tion to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A multiscale rule comprising a hollow elongated housing of arcuate cross-sectional form, said housing consisting of a pair of thin plates each being arcuate in cross-section, arcuate spacers forming end walls of the housing and secured to said plates holding said plates apart to form longitudinal entrances along two edges of said housing, a plurality of elongated thin blades nested within said housing and being curved in crosssection, said blades having various scales thereon, means secured to said blades for pushing said blades through said entrances to bring a selected scale into view, said means comprising a finger grip member secured to each blade, said housing having openings through which said members pass, locking means for said blades connected with said members and said housing, each blade provided with a slot extending transversely of the blade, and a guide carried by said housing and located in the slots of said blades.

2. In a multiscale rule, a hollow which includes an upper and a lower wall, means at the ends of said walls holding said walls spaced from each other to define longitudinal entrances along the edges of said housing, a plurality of elongated blades disposed in said housing and movable through both of said entances selectively, said blades having indicia thereon which is invisible when said blades are withdrawn into said housing and visible when projected through said entrances, said walls and said blades each being curved in cross-section so that said blades and walls nest with each other, each blade having separate means thereon for moving it through said entrances, locking devices operatively connected with each of said moving means to hold selected blades extended through the entrance on either side of said housing and within said housing, and guide means operatively connected with said blades and said housing to constrain the movement of said blades with respect to said housing.

3. The multiscale rule of claim 2 wherein said locking means includes an upstanding rib on said upper wall, and yielding means operatively connected between said upstanding rib and said separate means in order to hold said separate means and hence said blade to which it is connected for retaining said separate means in selected positions.

elongated housing References Cited in the file of this patent UNITED STATES PATENTS 2,322,248 Miller June 22, 1943 2,634,504 Jennings Apr. 14, 1953 2,672,692 Kucera Mar. 23, 1954 FOREIGN PATENTS 360,386 Germany Oct. 2, 1922 273,443 Great Britain July 7, 1927 126,509 Sweden Oct. 25, 1949

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