US614985A

US614985A - Drafting instrument

Info

Publication number: US614985A
Authority: US
Publication date: 1898-11-29
Anticipated expiration: 1915-11-29

Description

No. 6|4,985. Patented Nov. 29, |398.v

R. HUFFIN.- DBAFTING INSTRUMENT.

(Application led Aug. 18. 1897.)

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No. 64,985. Patented Nov. 29, |898. R. RUFFIN.

DRAFTING INSTRUMENT.

(Application Bled Aug'. 1B, 1897.)

(No Model.) 2 sheets-sheet 2.

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ROBERT RUFFIN, OF COMO DEPOT, MISSISSIPPI.

DRAFTING INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 614,985, dated November 29, 1898.

Application filed August 18, 1897. Serial No. 648,693. (No model.)

.To @ZZ wiz/0m it may concern,.-

Beit known that I, ROBERT RUFFIN, a citizen of the United States, residing at Como Depot, in the county of Panola and State of Mississippi, have invented a new and useful Drafting Instrument, of which the following is a specification.

My invention relates to drafting implements adapted for use in various lines of drafting, both general, as in mechanical work, and specific, as in geographical and topographical plotting and in the laying off of maps, obtaininglatitude and departure, and in various 0perations in connection with a plane table, and incidentally in the laying off of timbers in carpentry.

Various objects and advantages of this invention will appear in the following description, and the novel features thereof will be particularlyT pointed out in the appended claims. p

In the drawings, Figure l is a view of a drafting instrument constructed in accordance with my invention and designed especially for general work in connection with engineering and plotting. Fig. 2 is a detail view in perspective of the slide and the contiguous portion of the adjustable or hypotenuse arm. Fig. 3 is a detail section showing the connection between the adjustable or hypotenuse arm and the iixed perpendicular or latitudinal arm on line 3 3 of Fig. l. Fig. 4 is a detail sectional view of the slide and the joint between the same and the adjustable or hypotenuse arm on line 4 4 of Fig. 1. Fig. 5 is a view of a slightly modified and simpliiied form of the drafting instrument, also adapted for general work, but particularly designed for use in practical carpentry, for laying off roof and other timbers, ascertaining the pitch and length, as well as the terminal, vertical, and horizontal cuts thereof. Fig. G is a View of another modified form of the instrument embodying my invention, which is particularly adapted for use in connection with the plane table in geographical and topographical plotting.

Similar numerals of reference indicate corresponding parts in all the figures of the drawings.

In the illustrated embodiment of my invenh tion the essential features are a main or lon gitudinal arm carrying a perpendicular fixed latitudinal arm, an adjustable or hypotenuse arm having a sliding and pivotal connection with the main and perpendicular arms, or one of them, and an angle-gage arranged concentric with a pivotal point of the adjustable or hypotenuse arm, in connection with double verniers for accurately measuring fractional parts of lines and angles.

The form of instru ment which is illustrated in Figs. l to 4, inclusive, comprises a main or longitudinal arm l, to which is attached or integral with which is formed a fixed perpendicular or latitudinal arm 2, having a longitudinal slot 3, whereby the adjustable or hypotenuse arm 4 is adapted, by means of a locking device, such as a clamp 5, for adjustment at the adjacent end in a direction parallel with said latitudinal arm. The form of clamp illustrated in the drawings consists of a bolt or pivot-pin 6, extendingthrough the slot 3 and a corresponding longitudinal slot 7 in the adjustable or hypotenuse arm and tted with a thumb-nut 8. The slot 7 in the adjustable or hypotenuse arm provides for linear adjustment of said arm with relation to the Xed perpendicular arm 2, and the use of the pivot-pin 6 provides for pivotal movement of the adjustable or hypotenuse arm with relation to the fixed perpendicular arm 2. The opposite end of the adjustable or hypotenuse arm is pivotally and slidingly mounted upon the main or longitudinal arm l to provide for the adjustment of the said end of the hypotenuse arm with relation to the main or longitudinal arm to secure any desired angular position of the adjustable arm and any desired lengths of the base, altitude, and hypotenuse of the triangle formed by said main, perpendicular, and adjustable arms. In the construction illustrated the pivotal and sliding connection between the adjustable arm and the main arm is formed by means of a slide 9, fitted for linear adjustment upon the main arm l and having an extension or ear lO, (see Fig. 2,) upon which the contiguous extremity of the adjustable arm is pivoted, the slide consisting, essentially, of terminal guide-loops connected by a baseplate ll below the plane of the main arm and by a Vernier l2 above and contiguous to the uppersurface of said main arm. Fur- IOO thermore, the connection between the adjustable arm and the slide consists of a hollow or centrally-open pivot 13, consisting of an eyelet or any equivalent thereof arranged in such a position with relation to the slide that the fiducial or feather edge of the main arm spans the opening of the hollow pivot and lies accurately above the center thereof, or, in other words, occupies a position in a diametrical plane of the pivot, whereby in applying the instrument to a line or angle for measurement the center of the hollow pivot may be arranged overa given point in sight through the pivot. rlhe center of the hollow pivot is the point at which the inner or operative edge of the adjustable arm t intersects the inner or operative edge of the main arm. The function of the vernier in this connection is too well known to need explanation, it being obvious that its zero-point is transversely opposite the point of intersection of the operative edge of the adjustable arm with that of the main arm, or, in other words, is transversely opposite the center of the pivot, and the vernier being of the double type, whereby it may be read in either direction from the zero-point, according to the requirements of the measurement which is being taken. The base-plate 11, from which the ear 10 projects, is spaced from the lower sides of the guideloops of theslide, as shown in Figs. 2 and 4, to allow the contiguous pivotal extremity of the adjustable arm to operate between the base and the under surface of the main arm, by means of spacing-blocks 11a.

Carried by the base or other suitable portion of the slide is an angle-gage 14, disposed concentric with the pivot 13 and traversed by the adjustable arm, by comparison with which angles of detiection of the adjustable arm from the main arm may be measured, said angle -gage in the construction illustrated consisting of a quadrant-protractor. It is obvious that while the quad rant-protractor only is illustrated in Fig. 1 the extension thereof to the ordinary form of semicircular quadrant is possible without departing from the spirit of the invention, the advantage of such a modification residing in the fact that other angles than those at the base of a right-angled triangle could be measured, the peculiar construction of clamp which is employed for connecting the adjustable arm to the fixed perpendicular arm providing for the detachment of the former from the latter, and hence providing for swinging the adjustable arm to a position beyond that of a perpendicular to the main or to a position in which its inclination would be from instead of toward the fixed arm In the construction which I have illustrated in Fig. 5 the instrument is simplified by the omission of the angle-gage to adapt it particularly for use in practical carpentry, an important function ot' the instrument being in connection with the laying off of roof-timbers and the equivalents thereof. In the construction shown in Fig. 5 the main arm l, slotted perpendicular arm 2, adjustable arm 4t, the clamp 5", the slide 9, with its vernier attachment 12, and the pivotal connection 13 between the adjustable arm and the slide are equivalent to the corresponding parts described in connection with Figs. 1 to -l. To give an example of the use of this form of my invention, let it be supposed that it is required to obtain the lengt-h of a rafter for a hipped or gable roof having a span of sixteen feet and a rise or altitude of six feet. As each rafter will extend over a horizontal distance of one-half the span, the slide end of the adjustable arm should be arranged to bring the center of the pivot or the zero-point of the vernier over the graduation S of the main arm, (eight feet being one-half the spain) and the opposite cud of the adjustable arm should be adjusted with relation to the perpendicular arm to arrange the operative edge of the former at the graduation G of the latter, whereupon the length of the desired timber-namely, ten feetwill be indicated on the adjustable arm at its point of intersection with the operative edge of the perpendicular arm. It' now it is desired to obtain the bevel of the ends of the rafter cut to the desired length, the instrument may be used as a bevel and applied to the timber with the adjustable arm parallel therewith. The ed ge of the main arm will give the line of the horizontal cut of the timber, while the perpendicular arm will give the line of the vertical or perpendicular cut of the timber.

In the construction which I have illustrated in Fig. G the main arm 1b carries a slotted, fixed, or perpendicular latitudinal arm 2", which is extended in both directions from the main arm, and an adjustable arm 1h, mounted upon a slide 9, said adjustable arm being preferably duplicated, as indicated, and each adjustable arm having a cooperating semicircular angle-gage 14", carried by the slide. The latitudinal bar 2b is preferably mounted for sliding movement upon a guide-rib 15, arranged in a iixed position upon the plane table or other surface upon which the instrument is used and graduated to form a double vernier, said rib having terminal clips 1G, which overlap the surface of the latitudinal bar and hold the latter firmly against displacement, while allowing adjustment of said bar parallel with its length. Furthermore, the main bar or blade 1b is preferably graduated continuously from end to end in opposite directions at its upper and lower edges, respectively, and is also provided with a central line of graduations having an initial point at an intermediate part of the bar and being increased in opposite directions from this central point. This construction, in connection with the slide with its vernier 121', enables the operator to plot in either direction or from a central point in both directions, and hence enables him to obtain the latitude and departure of a line running in any direc- IOO IIO

IIS

tion from either a side or an intermediate initial point. In this form of my invention I preferably provide each adjustable arm with a Vernier 17 for use in connection With the angle-gage traversed thereby, and as in geographical and topographical plotting, for which the form of instrument illustrated in Fig. 6 is especially design/ed, it is ordinarily unnecessary to have the adjustable arm terminally connected to a perpendicular arm or latitudinal bar I preferably construct the adjustable arm 4l of only sufcient length to extend slightly beyond the peripheries of the angle-gages or protractors.

The operation of either of the forms of my instrument in determining the latitude and departure of a roof or run will be readily understood by those familiar with the art, it being obvious that the measurements upon the perpendicular arm will indicate the latitude and the measurements upon the main arm the departure When the adjustable arm is arranged to agree with the direction of the line to be measured. In the constructions illustrated in Figs. 1 to 5, inclusive, it is designed to measure latitude and departure by the measurements on the perpendicular and main arms when the adjustable arm is arranged to agree with the run, in which case the length of the run will be indicated upon the adjustable arm; but in the construction illustrated in Fig. 6 it is necessary in order to obtain the latitude and departure of a line to first adjust the slide to arrange the Zeropoint of the Vernier over one terminal of the line and then slide the instrument upon the guide-rib 15 a sufficient distance to bring the operative edge of the main arm to the other terminal of the line, whereupon the distance between the zero-point of the Vernier and the second-named extremity of the line Will give the departure, While the latitude Will be indicated by the distance through which the perpendicular arm 2b has been moved, the graduations thereon being compared With the Vernier on the guide 15.

Furthermore, it Will be understood that While in accurate Work it is desirable, and in fact necessary, to employ verniers or the equivalents thereof at the various points indicated, I do not desire to be limited to the use thereof, as any other suitable indicatingpoints may be employed when the definite accuracy necessary in close Work in plotting, engineering, die. is not required; and it is obvious,furthermore,that various other changes in the form, proportion, and the minor details of construction may be resorted to Without departing from the spirit or sacrificing any of the advantages of this invention.

Having described my invention, what I claim is- 1. A drafting instrument having a longitudinal bar, a slide mounted for adjustment upon said bar and comprisingabase arranged below the plane of the bar, terminal guideloops connected by said base and fitted upon said bar, and a double-Vernier bar connecting the guide-loops above the plane of the longitudinal bar, said base being extended to form an ear 10 and an angle-gage 14, and an adjustable arm pivotally mounted upon said ear by means of a hollow pivot, of which the center is in the plane of the fiducial edge of said longitudinal bar, substantially as specified.

2. The herein described drafting instrument comprising perpendicularly-disposed rigidly-connected longitudinal and

latitudinal arms

1 and 2, a slide mounted upon the longitudinal arm and having spaced guideloops connected, contiguous to the plane of the upper surface of the longitudinal arm, by a Vernier-bar7 said slide carrying an angle-gage, an adjustable or hypotenuse arm pivotally mounted upon said slide and intersecting the latitudinal arm, and means for clamping the hypotenuse and latitudinal arms at their point of intersection, the said hypotenuse arm being adjustable longitudinally, laterally, and angularly With relation to the latitudinal arm, substantially as specified.

In` testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two Witnesses.

ROBERT RUFEIN.

Witnesses:

T. O. HUNTER, Trios. H. TAYLOR.