Area demonstration device

Abstract

The area demonstration device belongs to the field of mathematical teaching aids. The prior art has the disadvantages of short service life, limited demonstration range, and lack of intuitiveness. The technical solution adopted by the present invention is: an area demonstration device, including a panel, characterized in that: a first sliding rod is provided with a first fixed end and a second fixed end, a rubber rope crosses a fixed pulley, one end of the rubber rope is connected to the first fixed end, and the other end of the rubber rope is connected to the second fixed end. The present invention is not easy to damage, has a long service life, a large demonstration range, and intuitively and vividly demonstrates knowledge points related to area.

Description

Technical Field

[0001] The invention belongs to the field of mathematics teaching aids. Background Art

[0002] For many years, the inventor has been using self-made teaching aids to explain the knowledge of triangle area, see the device described in publication number: CN203376903U for details. However, this device has many shortcomings, for example: the teaching aid has a short service life and is easily damaged. It should be noted that the cause of the damage is the inherent design deficiency rather than the material itself. Another example: the teaching aid has a very limited demonstration range and poor persuasiveness (or demonstration effect). Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the present invention proposes an area demonstration device, and the technical solution of the present invention is as follows:

[0004] The area demonstration device comprises a panel, a first fixed end, a second fixed end, a rubber rope, a slider, a first slide bar, and a second slide bar, wherein the panel is located on a vertical plane, the panel is fixedly connected to a horizontally arranged first slide bar, and the first slide bar is parallel to the panel plane.

[0005] The panel is also provided with a second sliding rod, which is arranged parallel to the first sliding rod, and the length of the first sliding rod from the panel is equal to the length of the second sliding rod from the panel.

[0006] The second slide rod is provided with a slider that can slide along the slide rod. In the direction of the slider toward the first slide rod, the slider is provided with a fixed pulley, and the straight line where the fixed pulley shaft is located is perpendicular to the panel.

[0007] The first sliding rod is provided with a first fixed end and a second fixed end. The rubber rope crosses the fixed pulley. One end of the rubber rope is connected to the first fixed end, and the other end of the rubber rope is connected to the second fixed end.

[0008] Further:

[0009] The cross section of the rubber rope is circular, and the cross section diameter of the rubber rope when it is not stretched is R.

[0010] It also includes multiple spheres, each with a diameter of R.

[0011] The ball fills the area enclosed by the rubber rope and the first slide rod, and the ball fills the area enclosed by the rubber rope and the first slide rod. In order to prevent the ball from rolling down, a transparent plate is provided, and the plane where the transparent plate is located is parallel to the plane where the panel is located.

[0012] Furthermore, the distance between the transparent plate and the panel is d, d is greater than R, and d is less than R+1 mm.

[0013] The transparent plate and the panel are fixedly connected.

[0014] The sphere is located between the transparent plate and the panel.

[0015] Further:

[0016] The sphere is made of a material that can be attracted by a magnet, and a plate-shaped permanent magnet is arranged between the sphere and the panel.

[0017] The invention is not easy to be damaged, has a long service life, has a large demonstration range, and can intuitively and vividly demonstrate area-related knowledge points. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention.

[0019] Figure 2 It is a schematic diagram of the structure of the present invention.

[0020] Figure 3 It is a top view of the present invention.

[0021] In the figure: 1- panel, 21- first sliding rod, 22- second sliding rod, 31- first fixed end, 32- second fixed end, 4- rubber rope, 5- slider, 6- fixed pulley, 7- ball, 8- transparent plate, 9- permanent magnet. DETAILED DESCRIPTION

[0022] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0023] Embodiment 1:

[0024] See attached Figure 1 , is a schematic diagram of the structure of the present invention. The figure shows: an area demonstration device, including a panel 1, a first fixed end 31, a second fixed end 32, a rubber rope 4, a slider 5, a first slide rod, and a second slide rod, wherein: the plane where the panel 1 is located is a vertical plane, the panel 1 is fixedly connected to a horizontally arranged first slide rod 21, and the first slide rod 21 is parallel to the plane where the panel 1 is located,

[0025] The panel 1 is further provided with a second slide rod 22, which is arranged parallel to the first slide rod 21, and the distance between the first slide rod 21 and the panel 1 is equal to the distance between the second slide rod 22 and the panel 1.

[0026] The second slide rod 22 is provided with a slider 5 that can slide along the slide rod. In the direction of the slider 5 toward the first slide rod 21, the slider 5 is provided with a fixed pulley 6. The straight line where the fixed pulley 6 rotation axis is located is perpendicular to the panel 1.

[0027] The first slide rod 21 is provided with a first fixed end 31 and a second fixed end 32 . The rubber rope 4 crosses the fixed pulley 6 . One end of the rubber rope 4 is connected to the first fixed end 31 , and the other end of the rubber rope 4 is connected to the second fixed end 32 .

[0028] Why can the method of embodiment 1 extend the service life of the teaching aid? Because the teaching aids of the prior art are prone to one of the rubber ropes 4 being broken when the slider 5 has a large range of movement. Then someone will ask: Why don't you make the rubber rope 4 longer? The answer is: If it is longer, it cannot be stretched straight and cannot be surrounded into a triangle. Someone else asked: Why don't you use a rubber rope 4 made of good materials? The answer is: No matter how good the material used to make the rubber rope 4 is, the probability of the rubber rope 4 being broken in the teaching aid disclosed in the prior art is much greater than that of the solution using the fixed pulley 6! After using the fixed pulley 6, only one rubber rope 4 is needed, while the prior art uses two rubber ropes 4. Usually, using two rubber ropes 4 is stronger than using one rubber rope 4. However, the present invention uses one rubber rope 4, and through the conduction of the fixed pulley 6, the length of one rubber rope 4 is automatically distributed on both sides of the fixed pulley 6, which greatly extends the service life. This itself overcomes technical prejudice.

[0029] Why is the demonstration range of the first embodiment increased? In the teaching aids disclosed in the prior art, when the slider 5 has a large movement range, one of the rubber cords 4 is easy to return to its original length and then bend, resulting in the area surrounded by the two rubber cords 4 no longer being a triangle. Of course, the other rubber cord 4 is also easy to break. In the present invention, as long as the rubber cord 4 does not break (which is very easy to achieve!), the area surrounded by the rubber cord 4 and the first slide rod 21 is always a triangle. The large demonstration range refers to the long distance that the slider 5 slides along the second slide rod, such as: close to the end point of the second slide rod.

[0030] That is to say, the use of one rubber rope 4 solves two technical problems at the same time, achieving the technical effects of increasing the service life and widening the demonstration range.

[0031] Of course, after reading this specification, those skilled in the art should know that in order to ensure that the area enclosed by the rubber rope 4 and the first slide rod 21 is closer to a triangle, the diameter of the fixed pulley 6 should be small enough, for example, the diameter of the fixed pulley 6 is 3-5 mm. As a teaching aid, for teaching, the highlight is the knowledge point itself.

[0032] Embodiment 2

[0033] However, the first embodiment still has some shortcomings: the demonstration of the knowledge point of unchanged area is not intuitive enough! Therefore, the inventors designed filling balls 7. If the balls 7 are filled, the area occupied by the balls 7 is the area of ​​the triangle.

[0034] See attached Figure 2 , is a schematic diagram of the structure of the second embodiment. In the figure: the cross section of the rubber rope 4 is circular, and the cross section diameter of the rubber rope 4 when not stretched is R,

[0035] It also includes a plurality of spheres 7, each sphere 7 has a diameter R.

[0036] The ball 7 fills the area surrounded by the rubber rope 4 and the first slide rod 21, and the ball 7 fills the area surrounded by the rubber rope 4 and the first slide rod 21. In order to prevent the ball 7 from rolling down, a transparent plate 8 is provided, and the plane where the transparent plate 8 is located is parallel to the plane where the panel 1 is located.

[0037] Further, the distance between the transparent plate 8 and the panel 1 is d, and d is greater than R. Further: and d is less than R+1 mm, which is better.

[0038] The transparent plate 8 and the panel 1 are fixedly connected.

[0039] The sphere 7 is located between the transparent plate 8 and the panel 1 .

[0040] In the process of pulling the slider 5, the slider 5 moves along the second slide rod 22, and the slider 5 drives the fixed pulley 6 to move. After reading this specification, those skilled in the art can easily know that the rotating shaft of the fixed pulley 6 and the slider 5 remain relatively still. In the process of the fixed pulley 6 moving, the base of the triangle remains unchanged, the height of the triangle remains unchanged, and the ball 7 always fills the triangle and fills it up. This shows that the area has indeed not changed.

[0041] This design enables the teaching aid to immediately have the function of quantitative measurement! Because the teaching aids disclosed in the prior art cannot measure the unchanged area, the technical solution of the second embodiment, by using the balls 7 to fill the triangular area, uses the conclusion that the number of balls does not change, and quantitatively knows that the area of ​​the triangle does not change. Compared with the prior art, this teaching aid is a qualitative leap from the perspective of measurement, and is an outstanding substantive feature and a significant improvement.

[0042] Embodiment 3

[0043] Although the teaching aids described in the second embodiment have made a qualitative leap compared to the prior art, they still have major shortcomings: in order to allow students to see the demonstration clearly, the panel 1 is placed vertically. In the process of pulling the slider 5, the ball 7 is very easy to get stuck due to the gravity of the ball 7, which causes the slider 5 to be unable to be pulled or the triangle to become a quadrilateral. Imagine: a layer of balls 7 is laid flat on a horizontal table. We use a baffle to gently push the balls 7 to move the balls 7 as a whole. Assuming that the table is tilted, use the baffle to push the balls 7 from bottom to top, and the balls 7 are easy to stack together.

[0044] In order to solve this technical problem, the inventor has made further optimization for the second embodiment, which has achieved very good results. Figure 3 , is a top view of the third embodiment, in which: the ball 7 is made of a material that can be attracted by a magnet, and a plate-shaped permanent magnet 9 is arranged between the ball 7 and the panel 1. Figure 3 In the embodiment, some parts are omitted, which does not affect the understanding of the third embodiment.

[0045] It should be noted that there are two types of steel balls sold on Taobao website, one is that magnets do not attract, and the other can be attracted by magnets. The present invention needs to buy steel balls that can be attracted by magnets, preferably with a diameter of 3-4 mm. The rubber rope 4 used in the present invention is also purchased from a Taobao store, and its product name is fluorine rubber strip, and its diameter is preferably 3-4 mm. The transparent panel 1 uses an acrylic plate. The permanent magnet 9 described in Example 3 is also sold on Taobao, and its product name is magnetic soft blackboard stickers. This material is easy to process into the required shape and size. The magnetic soft blackboard stickers usually sold are black or green. When making this teaching aid by yourself, you can add a coating or cover it with paper to change the color of the exposed surface.

[0046] Although the gravity of the ball 7 still exists, the ball 7 is attracted by the permanent magnet 9, the ball 7 no longer piles up, and no longer gets stuck, and the position of the slider 5 is changed, and it becomes very smooth. Using the teaching aid described in the third embodiment is really a very pleasant teaching experience.

[0047] Those skilled in the art should know that the rubber rope should be stretched straight for use. It should also be known that the balls 7 should be arranged in contact with each other in a plane or a layer, and should not be stacked.

[0048] Those skilled in the art should also know that: after the panel is attached with the permanent magnet, the permanent magnet and the panel appear to be a whole to the observer. Those skilled in the art should also know that the ball should be surrounded by the rubber rope, the first slide rod, and the transparent plate so as not to fall out.

[0049] The present invention has a long service life, a large range of variation of the slider 5, and intuitively and quantitatively demonstrates the knowledge point of area. Moreover, the teaching aid is smooth to use without jamming, and is really a good helper for mathematics teachers.

Claims

1. An area demonstration device, comprising a panel, a first fixed end, a second fixed end, a rubber rope, a slider, a first slide bar, and a second slide bar, wherein: The plane where the panel is located is a vertical plane, and the panel is fixedly connected to a first sliding rod arranged horizontally, and the first sliding rod is parallel to the plane where the panel is located. The panel is also provided with a second sliding rod, which is arranged parallel to the first sliding rod, and the length of the first sliding rod from the panel is equal to the length of the second sliding rod from the panel. The second slide rod is provided with a slider that can slide along the slide rod. In the direction of the slider toward the first slide rod, the slider is provided with a fixed pulley, and the straight line where the fixed pulley shaft is located is perpendicular to the panel. The first sliding rod is provided with a first fixed end and a second fixed end, the rubber rope crosses the fixed pulley, one end of the rubber rope is connected to the first fixed end, and the other end of the rubber rope is connected to the second fixed end; in the process of pulling the slider, the slider moves along the second sliding rod, the slider drives the fixed pulley to move, and the rotating shaft of the fixed pulley and the slider remain relatively stationary; The cross section of the rubber rope is circular, and the cross section diameter of the rubber rope when it is not stretched is R. It also includes multiple spheres, each with a diameter of R. The ball fills the area enclosed by the rubber rope and the first slide rod, and the ball fills the area enclosed by the rubber rope and the first slide rod. In order to prevent the ball from rolling down, a transparent plate is provided, and the plane where the transparent plate is located is parallel to the plane where the panel is located. The transparent plate and the panel are fixedly connected. The sphere is located between the transparent plate and the panel; The sphere is made of a material that can be attracted by a magnet, and a plate-shaped permanent magnet is arranged between the sphere and the panel; in the process of pulling the slider, the sphere is attracted by the permanent magnet, the sphere no longer stacks together, no longer gets stuck, and the position of the slider can be changed smoothly.

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