US520003A

US520003A - Wilhelm lehnek

Info

Publication number: US520003A
Authority: US
Publication date: 1894-05-15
Anticipated expiration: 1911-05-15

Description

2 Sheets-Sheet 1.

(No Model.)

W. LEHNER. ELLIPSOGRAPH.

(No Model.) 2 Sheets-Sheet 2.

W. LEHNER.

ELLIPSOGRAPH. No. 520,003. Patented May 15,1894.

flew?" ilNrTEn STATES PATENT OFFICE.

'WILHELM LEHNER, OF MUNICH, GERMANY.

ELLIPSOGRAPH.

SPECIFICATION forming part of LettersPatent No. 520,003, dated May 15, 1894.

Application filed July 14, 1893. Serial No. 1:80.503. (No model.)

To aZZ whom it may concern:

'Be it known that I, WILHELM LEHNER, electrical student, of 45 I Amalienstrasse, in the city of Munich, in the Empire of Germany, have invented new and useful Improvements in or Connected with Ellipsographs, of which the following is a specification, reference beng had therein to the accompanying drawlngs.

My invention relates to improvements in or connected with ellipsographs and consists n an ellipsograph whose construction isbased 0n the planimetrical principle herein described with reference to the diagram Figure 7 in the accompanying drawings.

It the end point Pk of a line P7t,Pg, describes a circle while the other point Pg moves along a straight line G passing through the center of the circle, the several points of the straight line Pk,-Pg between the two end points, for instance the point P, will describe ovals. These ovals become ellipses, when, in every position of the line, the point P that describes the oval is moved parallel to the straight line G toward P so that the lines P0cPy PP and P P 850., remain constant being out by the perpendicular lines from Pit and P to the line G at equal distances apart.

In the accompanying drawings Fig. 1, is an elevation of an ellipsograph constructed 1n accordance with my invention. Fig. 2, is a plan view of the same. Fig. 3, is a section on line 3-3 of Fig. 1. Fig. 4:, is a section on line 4--:t. Fig. 5, is a section on line 55, and Fig. 6, is a plan of the disk a (Figs. 2 and 4t), and Fig. 7 is a diagrammatic View lllustrating the construction of the ellipse.

On this principle is based the construction of the ellipsograph forming the subject of this invention which is illustrated in the accompanying drawings.

The main portion of the instrument is formed by a framing which consists of two end portions a and two side portions 12, and carries in the middle the elevated longitudinal stirrup bar 0. This bar 0 is perforated for the purpose of receiving a crank mechanism which is illustrated in sectionin Fig.

5. A crank handle 6 is fixed on the square portion of the spindle or stud z. The lower portion of the pin serves as a guide for the of the spindle or stud z, and can be fixed by means of the set screw 01 (Fig.1). On the end of the horizontal arm f isa pin 2 which when the crank handle is rotated carries one end of a rod .9 round with it in a circle. At its other end the rod 8 moves by means of the sliding piece 9 along the stirrup bar 0. Thus the rod 8 corresponds to the line Z shown on (Fig. 7). On sis the movable sliding piece 9" which is capable of being fixed by a set screw and is furnished with the pin h. The movable sliding piece 9 and with it the pin it describes when the crank handle is rotated an oval according to the planimetrical construction. Now this oval is converted by the ellipsograph forming the subject of this in vention into an ellipse with the help of the following parts. The frame 1! slides with its guides at (Fig. 4:) along the bars I) which are parallel to the stirrup bar c. The distance P-P Fig. 7, or the distance between the perpendiculars from P and P upon Gwhich is a constant, is represented in the ellipsograph by the distance of the longitudinal centers of the two slots 11' and t" which are set or rendered invariable or fixed when the ellipsograph is in use. In one slot 11 the pin 2 moves correspondingly to Pk (Fig. 7) along an arc of a circle and carries with it the frame '5 and cross bar q withtheir slots v1 and t'" which correspond to the perpendiculars from P70 and P upon G (Fig. 7). Now the sliding piece g which describes the ellipse is fitted in the slot t" so that it (g') can slide along the cross piece q and the said sliding piece 9 is provided with the slott (parallel to the elevated longitudinal stirrup bar 0) in which the pin h of the movable sliding piece g works and the said movable sliding piece g is operated by the pin it. The part 9 carries a vertically movable lead pencil-holder which is weighted with a weight 70 (Fig. 4:). The said lead pencil-holder can be raised clear of the paper when required and be kept in the raised position by the engagement of a nose or catch on in a disk u.

The abscissa produced by the sliding piece g and the point of the lead pencil is fully determined by the position of the pin a (corresponding to the point Pic Fig. 7) and by the constantly preserved distance of the centers of the two slots 71' and i" from each other and this distance corresponds to the two perpendlcular lines from Pit and P to the line GPoc (Fig. 7). Since the ellipse is formed from the oval by the movement of the several points of the latter parallel to G (Fig. 7) therefore analogously the sliding piece g is provided with a groove 25 parallel to c in which groove the pin h moves.

The use of the apparatus is as follows: The major and minor axes of the ellipse to be described being given, the horizontal arm f is moved until the distance of two markers or indicating lines 0 and 0' from each other 1s equal to half the major axis (the markers 0 0' having been moved out an equal distance from d and z) and the arm is then fixed by such that the horizontal arm f is at right angles with the stirrup bar a; then the cross arm qand the sliding piece 9' are moved until the point of the lead pencil comes over a line drawn parallel to the major axis through the end point of the half of the minor axis. Then the cross arm q and the movable sliding piece 9" are fixed by means of the set screws; the sliding clamp r is removed from the hand crank e and the handle of the hand crank e is moved round in a circle, whereupon the point of the lead pencil describes the mathematically exact ellipse required.

What I claim, and desire to secure by Letters Patent of the United States, is-

An ellipsograph comprising the main frame, a supplemental frame sliding thereon, a central bridge piece 0, having vertical crank shaft WILHELM LEHNER.

Witnesses:

O'rro BAOHMAYR, EMIL STAIGEY.