US1541179A - Device for use in teaching geometry or trigonometry - Google Patents

Description

Patented'lune 9, 1925.

UNITED STATES GEORGE A. PAR-KINSON, F MADISON, WISCONSIN.

DEVICE FOR USE IN TEACHING GEOMETRY OR TRIGONOMETRY.

Application filed A ril 17, 1924. Serial No. 707,086.

To all whom it may concern:

Be it known that I, GEORGE A. PARKIN- soN, a citizen of the United States, residing at Madison, in the county of Dane and 6 State of Wisconsin, have invented a certain new and useful Improvement in Devices for Use in- Teaching Geometry or Trigonometry, of which the following is a specification.

It is frequently the case with the youthful mind that it is lacking in the necessary imaginative power to grasp the significance of mere drawn lines and their proposed superposition upon each other especially, for

example, as where equal angles or equal triangles are to be proved such. Minds of this kind can often be helped if such lines, angles &c. be represented in tangible form. Hence it is the object of the present invention to provide an apparatus whereby lines, angles &-c. of various sorts are represented in concrete form and the parts of the apparatus manipulated to illustrate many of the elementary geometrical and trigonometrical terms and processes employed in making the proofs necessary in 'those branches of mathematical science.

The invention is embodied in the example herein shown and described, the features of novelty being finally claimed.

In the accompanying drawing- Figure 1 is a plan view of several parts of my apparatus connected together in a manner adapted to illustrate many of the terms of geometry and trigonometry.

Fig. 2 shows the main frame which is hinged to fold on two axes spread out in edge view.

Fig. 3 shows the same frame folded on one of its axes.

Fig. 4 illustrates a bar to be applied to the frame and,

Figs. 5, 6 and 7 arcuate pieces of 30, 45, and 60 degrees respectively that may also be applied to the main frame.

Fig. 8 is a cross section of one of the right angle arms at a slot therein showing a clamping device applied thereto.

Fig. 9 is a detail view of a suspending means for the frame.

The main frame is composed of four right angled pieces 10 conveniently of equal size and of like shape joined together in the form of a cross by hinges at 11 and 12 so that, for example, the left hand pair can be ro- 55 tated on the hinges 11 to lie on the right hand pair with the angles of the pairs coinciding; or, for example, so that the lower pair can be rotated on the axis of the hinges 12 to lie over the upper pair with the angles of those pairs coinciding. In Fig. 9 is illustrated a device at 20 wherebythe frame may be conveniently hung on a nail ona wall or board. Said device consists of two leaves hinged together, one of said leaves having an eyelet extension, the eye of which, as well asthe axis of the hinge of the leaves referred to, lies in linewith the axis of the hinge at 11. This hanging device can be added if desired, by welding or otherwise securing it to the arms 10 of Fig. 1 and as illustrated in Fig. 9. When spread out flat on a table or hung upon a wall as by means of the hinged eyelet 20 at the vertical axis of the frame it is to be viewed as representing one straight line intersecting another at right angles and forming four right angles. In this position also it represents the axis of abscissas and ordinates or the entire angular magnitude about the origin of coordinates. In the construction shown the bar of each of the angle pieces can be formed of sheet metal or other suitable material l 'lshape'in cross section and provided with a slot 14 so as to receive at its hollow or groove side asquare nut 15 k provided with a. fixed screw 16 that projects through the slot and receives a milled nut 17 whereby another member such as a rod Fig. 4 or an are as in Figs. 5, 6 or 7 can be fixed to the angle piece. The square nut can be slid along the groove in which it is located and because it fits it is held from turning when the milled nut 17 is turned to clamp the parts together. The rod and the arcs are each shown as provided with a series of perforations such as seen at 18 through any of which the screw of the clamping means can be passed to secure it in position. A perforation at 19 near the corners of each of the angle bars permits the attachment of a rod to illustrate angles greater or less than a right angle.

In Fig. 1 is illustrated some of the many ways in which rods and arcs can be applied to the frame and it will be observed by those familiar with mathematics that as shown in this view there are illustrated tangents, a square, several triangles, a trapezium, sectors, sines, cosines, abscissa-s, ordinates, and other features. In the practical use of the device it would not be necesszuiy or ierhaps desirable, to apply at one time as many of the members as are shown applied in Fig. 1 but only that or those required in a singie illustration or demonstration. By means of the perforations in the bars their position can be changed or they can be shifted to change the angular magnitudes and the forms cl any of the figures to be represented as may be desired or deemed advantageous by the instructor using the apparatus. The lamping of an applied member at one point will usually sufiice for practical purp sec it the equality of two angles or trianig similarity o't is to be shou i perposition the appropriate rods connected in symmetrical or similar arrangement to adjoining right a H ed pieces and these folded together. It ti o difference between two given angles or figures is to be shown this can likewis demonstrated by superposition.

ihe device can be manu' *tured out of thin strips of sheet metal and more oi the parts than show; and in diiierent forms or s'izescan be furnished with a set For example arcuate pieces cut on d f" mnt radii can be added.

The forms oi? th without departing vention as claimed.

What I claim is:

l. An apparatus adapted for use in ing geometry or trigonon'ietry compiframe composed of angle members hi1 their sides to each other to permit coinciding superiiiosition, one oi said angle members provided with a slot, a bar and means for aojustably securing said in said s ot,

2. An apparatus adapted if 'i' use in teaclu ing geometry or trigonometry comprising a frame con'iposed of four angle members hinged at their sidesto each other on two axes to permit coinciding superposition by rotation of pairs of the members on either of such axes. V

3. An apparatus adapted for use in (earliing geometry or trigonometry com irising a frame composed of four right angle members hinged together at .their sides on two axes to permit coinciding superposition by rotation of the members on either of such axes.

41-. An apparatus adapted for use in teaching geometry or tlIll'OllOITlQtlY comprising a 5 Irame composed 0i angle men'ibers hinged at their sides to each other to permit coinciding superposition and straight and arruate rods with means for securing them to one of said members.

An apparatus adapted for use in teachin geometry or trigonometry compr frame composed of angle members hing ed their sides to each other to permit coincidi115 superposition and straight and arcuate rods with means tor adjustably securing" them to one of said members.

6. tin api )aratiis adapted for use in teach ing geometry or trigonometry comprising): i rame composed of angle members hingeo together at paralieily arrange sides to pen mit ='=oinciding superposition and a h device for said frame consisting of a h l to said lelly arranged angular members and eye-bearing; member attache substantially with th line ot the axis of hinges ot' the i i devices.

7. 13.11 apparatus adapted for use in teaching geometry or mometry' comprising a frame composed of right angle members hinged together on lines at right angles to each other to representthe axes of abscissas and ordinates when exteude, said angled members adapted to 'iOltlQCl on either axis of hinging.

GEORGE A. PARKINSUN.

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