US1583138A - Topographer's rule - Google Patents

Description

May 4 1926.

F. M. GARNETT roroGRAPHERs RULE Filed Feb. 6 1925 rig/W dumm 1' 1 shows in Patented May 4 192 6. W v

UNITED STATES 1,583,138 PATENT OFFICE;

, FRED HELL GARRETT, O1 SAVANNAH, GEORGIA.

TOPOGRAPHERS RULE.

Application filed Iebi'uary e, 1925. Serial No. 7,883.

To all whom'z't may concern:

Be it known that I, FRED M. GARNETT, a citizen of the United States, residing at Savannah, in the county of Chatham and State of Georgia, have invented a new and useful Topographers Rule, of which the folving is a specification.

This invention aims to provide a .simple means whereby a topographer, working anywhere, but more especially in the field, may draw conventional signs rapidly, without shifting to any great extent, the scale whereby the distance from the transit to the object to be platted is laid off. I

It is within the province of the disclosure to .improve generally and to enhance the utility of devices of that sort to which the invention appertains;

Althou h a preferred form of the inven-* tion has en shown, it will be understood that an instrument maker, working within the scope of what is claimed, may make such changes as his skill may suggest,-without departing from the spirit of the invention. i

In the accompanying drawings:-Figure lan a device constructed in accordance with the invention; Figure 2 is a. cross section on the line 22 of Figure 1;

Figure 3 is a fragmentallongitudinal section; Figures 4, 5-and 6 are views illustrating some of the conventional signs 'which may be drawnby means of the instrument forming the subject matter of this application.

In carrying out the invention, there is provided astrip 1, made of any suitable material and provided along one edge with a scale 2, the strip 1 being beveled, if desired, as shown at 3, to that edge whereon the scale 2 is located. The strip 1 is provided at one end with a. hole 4, whereby the strip maybe suspended when not in use. The opening'4 is LOT the purpose-of attaching the rule to the topog'raphers coat or vest, whilst the rule is being used in the field. The rule, therefore, is not likely to be lost, as would be the case if it were ept in the pocket or carried in a note book. B

. suspending the rule with a string, it wil be available at all times for instant use, and

will not have to be put into the pocket.

The strip'1is provided with a plurality of opening's, so shaped that when a pencil is moved about the edges of the openings, conventional-signs will be formed. Having this consideration in' mind, the'strlp 1 has a rectangular opening 5, adapted to be used inthe drawing ofthe sign representing a railroad station or pavilion. Rectangular openings 6, 7 and 8, of different sizes, are provided, and the same are used for drawmg signs representing houses. An irregular rectangu ar opening9 is used for making the sign of a house of corresponding shape. The triangular opening 10 shown Figure 1 is useful for many purposes, for 4 instance, for indicating a triangulation point. The strip has a circular openingll surrounded by a concentric slot 12. These elements sometimes are. used in the representation of a hub or transit point. The numeral 14 marks a rectangular opening provided at its corners with diverging restricted slots 15. This opening, or a similar opening 17, are resorted to in the drawing of the sign 16 for abridge. A circular opening 18 having diametrically opposite slotted extensions 19 forms the sign for a telegraph pole. An arrow-shaped opening 20 produces the sign 21, indicating direc tion. The arcuate opening.31 is employed for 'indicatin curves of any kind, for instance m a highway. Arcu'ate slots 22 and 23, on difl'erent radii, have a utility which will be understood readily by those skilled in the art. l

The strip 1 is supplied with parallel slots a parabola or cycloid, so as to present thinned edges 30. It is clear that-when the pencil, shown diagrammatically in Figure.

3, is drawn along one of the slots 24, or along the slot 26, the pencil will ride up easily upon the br1dges'27, owing-to the fact that the br'dges have thinned edges 30,

' spaces being formed between the dashes in e sign 25 shown in Figure 4. Because the maximum height of each bridge 27 is less than thedepth of the slot, the pencil cannot jump out of the slot, as the pencil is drawnalong.

The device is made of a transparent substance. The trans arency of the rule enables the topograp erto sketch in the figures in their relative positions, since the center line of the survey is shown in the note book in red, all figures and approximate distances being referred to this line. Since it is possible for the topographer to see through the rule, the conventional signs may be oriented properly with. respect to the center line of the survey. It is suggested that the rule may be made out of xylonite or celluloid.

Having thus described the invention, what is claimed is A topographers rulesupplied with a slit, the rule being provided with spaced bridges extended across the slit, the height of the bridges being appreciably less than onehalf the thickness of the rule, the bridges having oppositely disposed thinned edges which coincide with the lower surface, of the rule, the upper surface of each bridge being continuously convexed from one of said thinned edges to the other, the slit being narrow enough to constrain a stylus "to right-line movement.

In testimony that I claim the foregoing as my own, I have hereto aflixed my signature.

FRED MELL GARNETT.

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