US1847997A - Ellipsograph compass - Google Patents

Description

March 1, 1932. w. G. BENNETT ELLIPSOGRAPH COMPASS Filed Sept. 12, 1929 W 6. Ben I: e a:

INVENTOR.

A TTORNEY. f

Patented Mar. It, 1932 tanner wnnno e. Bi nnnjrn'orsoarroosn, onneon eantime oonirnss Application filed September 12,1929. Serial No. 392,166.

The present inventionis directed to. improvements in compasses. r The primaryobjectof the invention is to provide an instrument of this character so constructed that ellipses of various sizes can be quicklyand accurately drawn. I 7

Another object of the invention is to provide an instrument of this kind so constructed that circles may be described, the instrument being capable of being adjusted for forming ellipses.

A further object of the invention is to provide an instrument of this'nature so con-v structed that a complete ellipse may be drawn upon imparting to the instrument a completerotation or twist.

With these and other objects in view,'th1s invention resides in the novel features ofconstruction, formation, combination and arrangement of parts to be hereinafter more fully described, claimed and illustrated in the accompanying drawings, in which:

Figure 1 is a perspective view of the device. Figure 2 is an enlarged detail sectlonal View through the casing.

Figure 3 is a sectional view on the'line 33 of Figure 1.

Referring to the drawings, 1 designates the leg of the device which'consists of alined upper and lower sections 2 and '3, respectively, the opposed ends of which are spaced.

and are provided, respectively, with lateral arms 1 and 5. A pair of upper and lower links 6 and? are employed and have their inner ends secured to the ends of the arms 4 and 5 by screws 8 which serve to hold the arms and links engaged with sufficient frictic-n to pre ventaccidental movement but permit relative adjustment when desired. 7

Pivotally mounted between the outer ends of the links 6 a transverse opening 10 formed therein and into which extends a set screw 11 which is adapted to engage the rod 12 slidable in the opening 10, said rod being connected with the leg 13. The upper end of the leg 13 has pivotally connected thereto, as at 14, 21 connector 15, which consists of telescopically connected sections 16 and 17, there being a coil spring 18 interposed between the upper and 7 is a cylinder 9 having end oi the section tiller 19 nou1ited ingthe upper end of the section 17, the latter telescopic connection. I I 7 Ti e filler 19 is pivotally connected, as at being of hollow formationto allow torithe 20, to thejbar 21 fixed to-the head 22, said headfharing a'knurled' knob23 carried thereby facilitate rotation.

The head 22is alined with .thesection 2 of the leg 1 and has fixed thereto abeveledggear 24-. A sim'i'largear 25-.is fixed to, the upper end ofthe section-20f said leg. A casing 26 is. provided which consists of separable com- I pleinentary sections 27 adapted to. engage in the grooves 28 and 29 formed, respectively,

of the casing are held together bybolts 30.

Extendingint o the casing is a shaft 31 which is journaled in the bearings-32 pro vided in the casing. v Loosely mountedon the in the head 22 and section 2. .Thesections 27 shaft are-beveled: pinions v33 which .mesh

with the gears 24 and 25, as clearly shown in Figure. 2 of the drawings. The shaft is provided with an arm 34in order that the shaft can be held. against rotation'with one hand while the other hand is employed for rotating the head 22-"througl1 the medium of the knob;

."The: action 3 of the'leg 1 is ained with a steeLpoint35 while the'leg 13 carries the head'36 :inwhich is mounted a lead point 37.:

- H The spring 18 will tend to urge the section 16 downwardly, thus holding the lead point 37in contact with thepaper.

When it is desired to form an ellipse, the links 6 and 7 are adjusted fortheproper size, whereupon the knob 34 is held firmly inone hand'while the knob 23 istwirledwith the other hand and owing to the differential action of the 33, an ellipse-can be easily and accurately formed j c Of course, when it isdesired to merely drawa circle, the knob 23 isturned synchronously withthe shaft 31.

In drawing an ellipse, it' will be noted that the leg 1 will rotate in onedirection while the connector 15 and leg 13 will rotate in a reversedirection, this being, of course, dueto gears 24 and 25 and the pinions the presence of the intermeshing gears 2 and 25 and pinions 33.

From the foregoing, it is thought that the operation and many advantages of the herein described invention'will be apparent to those skilled in the art without further description, and it will be understood that rious changes in the size, shape, proportions, and minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

What is claimed is:

1. A compass of the class described comprising a main leg consisting of upper and lower sections, a head, a connector pivotally connected-with the head, a second leg pivotally connected with the connector, links connected with the upper and lower sections of the main leg, a rod carriedby the second leg and adjustably connected with the links, and a gear assembly between the head and main leg sections to rotate the main leg and second leg in reverse directions.

2. A compass of the class described comprising a main leg consisting of upper and lower sections, a head, gears fixed to the opposed ends of the head and upper section of the leg, a shaf-textending between the gears, pinions loose upon the shaft and meshing with the gears, a second leg, a connector between the second leg and head, arms carried by the opposed ends of the upper and lower sections of the main leg, links connected with the arms, a rod projecting from said second leg, and means for adjustably connecting the rod with the links. H

3. A compass of the class described comprising a main leg consisting of upper and lower sections having arms carried by their opposed ends, a head alined with the main leg sections, a second leg pivotally connected with the head, means for adjustably connecting the second leg with the arms, a differentiel gear-assembly etween the head and'main leg operating to rotate the main leg and second leg in reverse directions.

e. A compass comprising a main leg formed of a pair of alined sections, a second leg, a head, a differential gearing between the head and one of the sections of the main leg, connecting means between the second leg and the head, and connecting means between said s cend leg s pai of. al ne e tines 02E he ma n leg- 5,. A compass comprising a main leg formed or" a pair of alined sections, a second leg, a head, a difierential gearingbetween he h ad nd n f the sec ions of th mai leg, moans pivotally connecting the second leg with the head, and a yieldable connection between said second leg and said pair of alined sections of the main leg.

6. A compass comprising a main leg formed of apair of alined sections, a head,

nee-ace? a casing forming connecting means between the head and one of the sections of the leg, a shaft passing between the head and said section of the leg and mounted in the casing and projecting to form a handle, a differential gearing between said section of the leg, said head and said shaft, asecond leg, means pivotally connecting the second leg with said head, and a yieldable connection between said second leg and said alined sections of the main leg.

In testimony whereof I afiix my signature.

WALDO G. BENNETT. 1 3.

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