CN2216930Y

CN2216930Y - Folding type appliance for geometry drawing

Info

Publication number: CN2216930Y
Application number: CN 94237426
Authority: CN
Inventors: 向金霞
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-05-19
Filing date: 1994-05-19
Publication date: 1996-01-10
Anticipated expiration: 2004-05-19

Abstract

The utility model discloses a multifunctional appliance for geometry drawing, which can be folded and can be used for mathematics teaching. The utility model has the structural characteristics that three rods are hinged together, when opened, the three rods can be used as a compass and a protractor, and when closed, the three rods can be used as a ferule and a ruler. The utility model has the advantages of simple structure, easy use and portability.

Description

Collapsible geometric ruler

The utility model relates to a kind of Geometric figure drawing instrument that is used for mathematical education, particularly a kind of can be how with and drawing teaching aid that can folding portable.

Teacher need draw different geometric figures lecture class hour how much for the student on blackboard, as line segment, angle, polygon, circle etc., also need to measure length and angle.Under normal conditions, teacher must be with multiple instruments such as set square (or ruler), protractor, compasses just can finish these work.In fact, class hour on the math teacher, need be with teacher's pointer, textbook, prepare lessons originally and chalk, add so many drawing instruments, bother very much, and use very loaded down with trivial details and time-consuming, also very inconvenient.

Task of the present utility model, a kind of folding geometric ruler will be provided exactly, is a teacher's pointer and ruler when it draws in, is again compasses and set square when opening, both can be used to draw line segment, polygon and circle arbitrarily, can measure length and angle again.

Task of the present utility model, finish as follows:

Three straight-bars that have special cross section, can inlay cover each other, hinged in twos, wherein a bar strand end can slide in another has the chute of bar of chute, when the hinge end of sliding bar in groove during the optional position, two bars will be formed " people " the font compasses and the protractor of different angles in addition; When the hinge of sliding arrives chute bottom the time, three bars constitute a right angle triangle, are equivalent to a right angle set square; When the hinge of sliding arrived chute the top, three bars overlapped into a teacher's pointer; Scale on the bar can be used for measuring the length of line segment and the angle of angle.

The utility model by adjusting its relative position, has just been given play to multiple functions such as being equivalent to set square, ruler, compasses, protractor, teacher's pointer with three hinged bars, and one-object-many-purposes is simple in structure, and operation rapidly, and is easy to carry.

Concrete structure of the present utility model is provided by following embodiment and accompanying drawing thereof.

Structural representation of the present utility model among Fig. 1.

To be respectively two embodiment with " U " tee section and " L " tee section closing up the sectional schematic diagram of adult education when whiplike for Fig. 2 and Fig. 3.

Describe detail of the present utility model and working condition thereof in detail below in conjunction with accompanying drawing.

Bar 1 and bar 2 have " U " or " L " shape cross section, and oval poroid chute A ' A is arranged on the bar 2 ", two bar cross section openings are relative, are articulated in C, and bar 2 can be inserted in the bar 1; Bar 3 is the square-section bar, and one end and bar 1 are articulated in B, and the other end and bar 2 are articulated in A.The A hinge is the thread that can regulate degree of tightness, can " come and go slip or fixing in the groove at A ' A; The 4th, the tip of bar 1, the 5th, a chalk sleeve on the bar 2.

Scale (length and angle) all can be arranged on bar 1, bar 2 and the bar 3.

When the A of bar 3 end " slides in the groove and when fixing certain some A (as shown in Figure 1) at A ' A

⑴ be the center of circle with the tip 4 of bar 1, can draw circle or arc with the chalk that is enclosed within bar 2 chalk sleeves 5, can make compasses and use.

(2) two straight lines and intersection point thereof are coincided with bar 3 and bar 2 and A point,, can measure the size of the two line angles of cut, also can read the number of degrees at the supplementary angle at this angle simultaneously by the angle index on the bar 2;

When the A of bar 3 end slides to A ' and tightens up thread A, form a right angle triangle, its function is equivalent to a right angle triangle, can draw straight line and pass through bar high scale slotted line segment length;

When the A of bar 3 end slides to A " time, bar 2, bar 3 are all inlayed and are placed in the bar 1, become a teacher's pointer, and also available ruler uses.

According to geometry knowledge, three pole lengths meet Pythagorean theorem.

Claims

1, a kind of by three hinged in twos geometric rulers of forming of bar, it is characterized in that:

1., the cross section of bar (1) and bar (2) is " U " or " L " shape, bar 2 can be placed in the bar (1), bar (3) can be inserted in the bar (2);

2., bar (1) and bar (2), bar (1) and bar (3) have an end to be hinged, the other end of bar (3) is articulated in sliding tray A ' A by a slip hinge A that can adjust degree of tightness with bar (2) " in, when the hinge of sliding A transferred pine, A holds can come and go slip in sliding tray.

2, geometric ruler according to claim 1 is characterized in that, bar (1) has a tip (4), and bar (2) has a chalk sleeve (5).

3, geometric ruler according to claim 1 and 2 is characterized in that, on bar (1) and the bar (3) the length scale is arranged, and bar has length and angle index on (2).

4, geometric ruler according to claim 3 is characterized in that angle index is marked on the straight line.