Quadratic curve drawing tool

Abstract

To provide a quadratic curve plotter capable of freely plotting graphs of quadratic functions (quadratic curves) with different rates of change by changing fixed positions of members constituting a device with simple operations.SOLUTION: A quadratic curve plotter comprises a frame, a guide member, a cross-shaped rotating member and a quasi-line moving member. The frame consists of a first frame and a second frame, graduated at predetermined intervals and arranged in parallel, the guide member consists of a central guide section, a focal point guide section and a quasi-line guide section, and the cross-shaped rotating member is configured to maintain verticality by a quadratic curve following section and an arm section.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a quadratic curve drawing instrument that freely draws graphs of quadratic functions with different rates of change, that is, quadratic curves with different opening sizes, using a simple mechanism.

Background Art

[0002] Conventionally, quadratic curves are studied in junior high school and high school in school education. Also, in industrial applications, it is typically used in the design of parabolic antennas.

[0003] In school education, the drawing of quadratic curves is performed by plotting the coordinates obtained by substituting numerical values into a given quadratic function on graph paper and connecting the plots using a ruler or freehand.

[0004] Currently, since there is no stationery that can accurately draw quadratic curves, junior high school or high school students often spend time and effort to make incomplete drawings such as broken lines using the above method.

[0005] If junior high school or high school students can freely draw the quadratic curve of a quadratic function given as an assignment, it is considered that their interest in quadratic functions will increase and their learning motivation will also increase. However, at present, stationery that can freely draw quadratic curves has not been realized.

[0006] On the other hand, in the industrial field, since it is necessary to draw a quadratic curve in the design of a parabolic antenna, a quadratic curve drawing device has been developed.

[0007] Fig. 10 shows a mechanism for drawing a quadratic curve in a prior art document. A parabolic antenna needs to reflect radio waves or light traveling through space onto the bowl-shaped reflecting surface of the parabolic antenna and concentrate them at the focus. Therefore, in the design of a parabolic antenna, the property that the distance from an arbitrary point on the quadratic curve to the directrix is equal to the distance from the arbitrary point to the focus is utilized or applied.

[0008] Specifically, a plotting tool has been developed and disclosed in prior art documents that uses or applies the relationship that the distance between a line PF, which is obtained by extending a line FE connecting the focus F of a quadratic curve to an arbitrary point E on the circumference of a circle tangent to the quadratic curve centered at F, to an intersection point P on the quadratic curve, and a line RpP, which is obtained by extending a perpendicular line PH from the intersection point P to the X-axis, to an intersection point Rp on the directrix DX, is equal. The dashed line PL in the figure is a line parallel to the X-axis passing through the focus.

[0009] According to the aforementioned properties, in Figure 10, the length of the line RpH is equal to the radius FE of the circle. Therefore, the length of the perpendicular PH is equal to the length of the line PE. If T is the intersection point of the tangent line of the quadratic curve passing through intersection point P and the line RpF, then the tangent line PT and the line RpF form a right angle. Similarly, the tangent line PT and the line EH form a right angle at intersection point S. Patent Document 1 discloses a quadratic curve generating tool that constructs a quadratic curve by manually moving the connection point E of the cross member with the circumference along the circumference, in a cross member equipped with a link mechanism composed of the tangent line PT (which may extend beyond intersection point P or intersection point T) and the line EH such that the right angle is maintained and point H moves along the X axis.

[0010] Furthermore, Patent Document 2 discloses a quadratic curve generating tool for a link element body, which is a link mechanism configured to maintain the equal lengths of the straight line RpP and the straight line PF using the aforementioned properties, and in which point Rp moves along the directrix DX, by manually moving the connection point T of the link element body, which is composed of a tangent line PQ and a straight line RpF, along the X-axis. Point Q is any point obtained by extending the straight line PT outside the intersection point T. Also, the tangent line PQ may be extended beyond the intersection point P. The symbols used in the above description are different from the symbols shown in Patent Document 2 and are based on Figure 10. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 1-113294 [Patent Document 2] Japanese Patent Application Publication No. 152498 / 1983 [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] Neither of the two prior art documents mentioned above describes how to change the size of the opening of a quadratic curve by changing the coefficient of the quadratic term of a quadratic function, i.e., the rate of change. Nor do they describe the configuration of an apparatus for changing the rate of change of a quadratic function. Therefore, there is a problem in that it is not possible to easily change the configuration of the apparatus to construct graphs (quadratic curves) of quadratic functions with different rates of change.

[0013] The present invention has been made in view of the above problems, and aims to provide a quadratic curve plotter that can freely plot quadratic function graphs (quadratic curves) with different rates of change by simply changing the fixed positions of the components constituting the device. [Means for solving the problem]

[0014] To solve the above problems, the present invention parabola The drawing device consists of a frame, a guide member, a cross-shaped rotating member, and a line-moving member. parabola A drawing instrument, the frame being composed of a first frame and a second frame, with scales marked at predetermined intervals, for drawing. parabolaThe guide members are arranged parallel to each other with a distance between their opening ends, and consist of a central guide section, a focus guide section, and a guide line section. The central guide section is spanned perpendicularly across the first and second frames and fixed in place. The focus guide section and the guide line section are movable on the first and second frames, and during drawing, they are spanned and fixed across the first and second frames at equal intervals from the central guide section. The cross-shaped rotating member consists of a quadratic curve following section and an arm section, and the quadratic curve following section and the arm section are fixed at approximately the center of the arm section while maintaining perpendicularity. The drawing member is rotatably fixed at approximately equidistant positions from the first and second frames on the central guide section, and is rotatably and slidably connected at the intersection of the arm section and the focus guide section, and the arm section and the line of reference guide section, so that the line of reference moving member maintains parallelism with the frame, and the drawing member is rotatably and slidably connected on the line of reference moving member at the intersection with the quadratic curve tracking section on the central guide section side, and is slidably connected on the line of reference guide section on the line of reference guide section side, and moves in the lateral direction along the line of reference guide so that the drawing member is on the paper parabola It is characterized by depicting [something].

[0015] Furthermore, the present invention parabola The drawing tool has a quadratic curve tracking section, parabola The device is characterized by having a two-layer structure consisting of a rotation axis in the fixed part and a part on which the drawing member slides, so as not to interfere with the movement of the drawing member.

[0016] Furthermore, the present invention parabola The drawing instrument is constructed by fixing the focus guide and the guide lines to the frame, while maintaining an equal distance from the central guide, and changing the distance from the central guide. parabola It is characterized by the fact that the size of the opening is changed. [Effects of the Invention]

[0017] According to the conic drawing instrument of the present invention, since there is no need to fix the focus of the conic during drawing, by moving the focus guide part and the directrix guide part in a state where the distances from the central guide part are kept at equal intervals according to the scales attached to the frame body, the rate of change of the quadratic function can be changed, and conics with different aperture sizes can be easily drawn.

[0018] Moreover, according to the conic drawing instrument of the present invention, although the pole of the conic is used as a fixed point, by constructing the moving members in layers, the drawing member can pass through the pole of the conic. Therefore, there is an advantage that it is easy for the drafter to imagine the shape of the conic drawn by the conic drawing instrument before drawing, and it has an effect of being suitable as a learning material.

Brief Description of the Drawings

[0019] [Figure 1] It is an external view of the conic drawing instrument 1 of the present invention viewed from the upper surface direction. [Figure 2] It is an external view of the conic drawing instrument 1 of the present invention viewed from the side surface direction. [Figure 3] It is a configuration diagram of the conic drawing instrument 1 of the present invention. [Figure 4] It is a schematic view of the conic drawing instrument 1 of the present invention viewed from the side of the second frame body 104. [Figure 5] It is a schematic view of the conic drawing instrument 1 of the present invention viewed from the side of the directrix guide part 126. [Figure 6] It is a perspective view showing the structure of the rotating part 42 and the wheel part 46 in the slide member 40. [Figure 7] It is a process diagram when drawing is performed using the conic drawing instrument 1 of the present invention. [Figure 8] It is a view showing a state where conics with different rates of change are drawn by changing the intervals of the guide members 12. [Figure 9] It is a graph of conics that can be drawn by changing the intervals of the guide members 12. [Figure 10]This diagram illustrates the mechanism for constructing quadratic curves in prior art literature. [Modes for carrying out the invention]

[0020] An embodiment for implementing the quadratic curve drawing device 1 according to the present invention will be described with reference to the figures. Figure 1 is an external view of the quadratic curve drawing device 1 of the present invention as seen from above.

[0021] The quadratic curve drawing device 1 according to the present invention consists of a frame 10, a guide member 12, a cross-shaped rotating member 20, and a line-moving member 30.

[0022] The frame 10 is composed of a first frame 102 and a second frame 104, with a guide member 12 spanning between the first frame 102 and the second frame 104. The upper surfaces of the first frame 102 or the second frame 104, or the first frame 102 and the second frame 104, are marked with scales 1022 at predetermined intervals. The first frame 102 and the second frame 104 are arranged parallel to each other, for example, with a distance between the open ends of the quadratic curve to be drawn, and the height distance from the drawing material, such as paper, is adjusted by the legs 14. The frame is then stably fixed to the plane on which the drawing material is placed using the ground contact parts 16.

[0023] The guide member 12 consists of a central guide section 124, a focus guide section 122, and a guide line section 126. The central guide section 124 consists of a rail section 50 on which a sliding member 40 can slide between frame fixing sections 128 provided at both ends in the longitudinal direction. The central guide section 124 is, for example, placed on a scale marked at a predetermined position for the central guide section 124 on the frame 10, spanning the first frame 102 and the second frame 104, and fixed by the frame fixing section 128. In Figure 1, it is positioned to align with the "0" mark on the scale. The focus guide section 122 and the guide line section 126, like the central guide section 124, consist of a rail section 50 on which a sliding member 40 can slide between frame fixing sections 128 provided at both ends in the longitudinal direction. With the central guide section 124 at the center, the focal guide section 122 passes through the focal point located on the inside of the quadratic curve, i.e., on the aperture side, and is parallel to the central guide section 124, while the directrix guide section 126 is positioned parallel to the central guide section 124 on the directrix outside the quadratic curve, maintaining an equal distance from the central guide section 124, and is movably spanned over the first frame 102 and the second frame 104, and is fixed by the frame fixing section 128 when drawing the quadratic curve.

[0024] The cross-shaped rotating member 20 is composed of a quadratic curve following section 22 and an arm section 24. The quadratic curve following section 22 has a rail section 50 on which a slide member 40 can slide in the longitudinal direction, and a rail stopper section 52 is provided at its end. Similarly, the arm section 24 also has a rail section 50 on which a slide member 40 can slide in the longitudinal direction, and a rail stopper section 52 is provided at its end. The quadratic curve following section 22 and the arm section 24 are fixed rotatably by a fixing section 26 at approximately the center of the arm section 24, at a position equidistant from the first frame 102 and the second frame 104 on the central guide section 124, while maintaining a vertical position in a plan view. Furthermore, the slide member 40 disposed at the arm section 24 at the intersection with the focal guide section 122 and the direct line guide section 126 is slidably mounted between the fixing section 26 and the rail stopper section 52 on the rail section 50 of the arm section 24. At the same time, the focus guide section 122 and the guide line section 126 are rotatably coupled to the sliding members 40. The rail section 50 of the quadratic curve following section 22 has a length that is approximately equidistant from the fixed section 26. The sliding member 40 that is coupled to the drawing member 60 provided on the guide line moving member 30 has a structure that allows it to move along the entire length of the rail section 50 of the quadratic curve following section 22, the specific reasons for this will be explained later.

[0025] The linear movement member 30 is equipped with a rail section 50 on which the drawing member 60 can slide in the longitudinal direction, and a rail stopper section 52 is provided at its end. With the linear movement member 30 maintaining its longitudinal direction parallel to the frame 10, it is rotatably connected to the rotating section 42 of the drawing member 60 via the rotating section 42 of the sliding member 40 provided on the quadratic curve following section 22 at the intersection with the quadratic curve following section 22 on the focal side (hereinafter referred to as the focal side) with respect to the central guide section 124. The drawing member 60 is also slidably attached to the rail section 50 of the linear movement member 30. With the central guide section 124 as a reference, on the parallel line side (hereinafter referred to as the parallel line side), a sliding member 40 that can slide freely is connected to the rail section 50 of the parallel line auxiliary guide section 1262 at the parallel line side end of the parallel line moving member 30. When the parallel line moving member 30 is moved in the longitudinal direction of the parallel line guide section 126 using the handle 32, the drawing member 60 draws a quadratic curve on the paper.

[0026] Figure 2 is an external view of the quadratic curve drawing device 1 of the present invention, viewed from the side of the second frame 104. The quadratic curve drawing device 1 has a six-layer structure, with the first layer being the frame 10 and guide member 12, the second layer being the arm 24, the third layer being the sliding auxiliary part 224 of the quadratic curve following part 22 (see Figure 3 or Figure 4), the fourth layer being the main body 222 of the quadratic curve following part (see Figure 3 or Figure 4), the fifth layer being the guideline auxiliary part 1262, and the sixth layer being the guideline moving member 30.

[0027] Figure 3 is a diagram of the configuration of the quadratic curve drawing device 1 of the present invention. Figure 3 is a diagram of the configuration as viewed from the same direction as Figure 2. To the left of the diagram of the first layer is a sliding member 40 that slides along the guide line section 126 attached to the frame 10. The × mark in the circle and the black circle shown in the central part of the sliding member 40 indicate that the sliding member 40 can slide freely in the depth direction towards the front or back of the diagram. That is, it indicates that the sliding member 40 can slide freely along the rail section 50 of the guide line section 126. The arrow attached to the shaft section 44 indicates that the shaft section 44 is constructed using a rolling bearing and can rotate clockwise or counterclockwise. Therefore, the sliding member 40 of the guide line section 126 is rotatably connected to the slide member 40 on the guide line side of the arm section 24 of the second layer via the shaft section 44. The sliding member 40 of the arm section 24 can also slide between the arm section 24 and the fixed section 26 in the center of the diagram. Furthermore, in the fifth layer, the shaft portion 44 is rotatably coupled to the slide member 40 provided on the rail portion 50 of the guideline auxiliary guide portion 1262. The slide members 40 provided on the guideline guide portion 126 and the guideline auxiliary guide portion 1262 are arranged to prevent axial wobble and other issues, thereby increasing the rigidity of the quadratic curve drawing device 1 and enabling accurate quadratic curve drawing, as the distance from the guideline guide portion 126 to the guideline moving member 30 increases in the layer direction. Since the guideline moving member 30 is fixed to the slide member 40 of the guideline auxiliary guide portion 1262, it can be moved in the longitudinal direction of the guideline guide portion 126, which is the direction in which the slide member 40 can move, by operating the handle 32.

[0028] The first layer center is a fixed part 26 fixed to the central guide part 124. The first layer fixed part 262 is connected to the second layer fixed part 264 located approximately in the center of the arm part 24 via a rotatable shaft part 44. Furthermore, it is rotatably connected to the third layer fixed part 266 of the slide assist part 224 of the quadratic curve following part 22.

[0029] On the right side of the first layer diagram is a sliding member 40 that slides along the rail portion 50 of the focus guide portion 122 attached to the frame 10. The sliding member 40 of the focus guide portion 122 is rotatably connected to the sliding member 40 on the focus side of the second layer arm portion 24 via the shaft portion 44.

[0030] Figure 4 is a schematic diagram of the quadratic curve drawing device 1 of the present invention, viewed from the side of the second frame 104. The cross-shaped rotating member 20 has a second layer fixing part 264 and a third layer fixing part 266 connected to the first layer fixing part 262 via a rotatable shaft part 44. The quadratic curve following part 22 has a two-layer structure consisting of a quadratic curve following part body 222 and a slide auxiliary part 224. The slide auxiliary part 224 is provided on a different layer from the quadratic curve following part body 222 so that the slide member 40, which connects to the drawing member 60 disposed on the linear moving member 30, can slide past the fixing part 26 and along the rail part 50 of the quadratic curve following part body 222 to both ends. More specifically, the rail part 50 on the left side of the quadratic curve following part body 222, from the fixing part 26 in the view of the figure, is through which the slide member 40, which connects to the drawing member 60 when drawing a quadratic curve in the quadratic curve in the quadratic curve on the first frame 102 side from the fixing part 26, passes. Furthermore, the rail section 50 on the right side of the quadratic curve following section body 222, extending from the fixed section 26 in the diagram, is through which the slide member 40, which connects to the drawing member 60 when drawing a quadratic curve in the quadratic curve in the quadratic curve on the second frame body 104 side of the fixed section 26, passes. The slide auxiliary section 224 extends parallel to the quadratic curve following section body 222 from the third layer fixed section 266 to a predetermined length, and is connected and fixed at its end to the end of the fourth layer quadratic curve following section body 222, so as not to be obstructed by the fixed section 26 by the movement of the slide member 40 that connects to the drawing member 60. The predetermined length is determined by the distance between the open ends of the quadratic curve to be drawn.

[0031] Figure 5 is a schematic diagram of the quadratic curve drawing device 1 of the present invention, viewed from the side of the directline guide section 126. The directline guide section 126 requires that the directline-side sliding member 40 of the cross-shaped rotating member arm 24 of the second layer and the directline moving member 30 of the sixth layer be coupled so that they can move synchronously in the longitudinal direction of the directline guide section 126. The distance from the second layer to the sixth layer is long, and if the directline moving member 30 is held only by the sliding member 40 of the directline guide section 126, the coupled shaft portion 44 may experience runout. Therefore, the directline guide section 126 is equipped with a directline auxiliary guide section 1262 to prevent runout of the shaft portion 44, and is positioned on the fifth layer directly above the sixth layer. Since the directline moving member 30 is equipped with a drawing member 60, runout of the shaft portion 44 of the directline guide section 126 that holds the directline moving member 30 affects the accuracy of the drawing and therefore needs to be prevented in particular.

[0032] The guide line section 126 and the auxiliary guide line section 1262 are joined and fixed to the outside of the first frame 102 and the second frame 104 so as not to interfere with the cooperative operation of the cross-shaped rotating member 20 and the guide line moving member 30. The fixing method is not limited to joining with spacers or the like, but any well-known method is acceptable.

[0033] Figure 6 is a perspective view showing the structure of the rotating part 42 and the wheel part 46 in the slide member 40. Figure 6 illustrates the connection between the quadratic curve following part 22 and the linear moving member 30. The slide member 40 is constructed by stacking two plate materials vertically, and the rail part 50 is sandwiched between the upper and lower plate materials. At the same time, the upper and lower plate materials are joined by sandwiching the wheel part 46. The wheel part 46 has the axis of the cylindrical bottom surface of the rolling bearing fixed to the upper and lower plate materials. The cylindrical side surface of the rolling bearing is fixed in rotatable contact with the surface of the rail part 50. In order to make the sliding of the slide member smooth, two wheel parts 46 are configured to be in contact with each rail part 50. In this embodiment, since the rail part 50 is constructed of two rod-shaped bodies, the upper and lower plate materials sandwich the rod-shaped bodies at both ends along the sliding direction, and two wheel parts 46 are provided on each side. The rail section 50 may be composed of a single rod-shaped body, which is then clamped between the wheel sections 46 on both sides. Furthermore, although the diagram shows a circular cross-section for the rail section 50, it may also be polygonal.

[0034] At the center of the slide member 40 in a plan view, there is a rotating part 42 equipped with a rolling bearing. The rotating part 42 is connected to the rotating part 42 of other slide members 40 via a shaft part 44. The slide members 40 provided on the focus guide part 122, the direct line guide part 126, and the arm part 24 have the same structure. Because the slide member 40 is equipped with a rotating part 42 and a wheel part 46, the cross-shaped rotating member 20 connected via the slide member 40 changes angle in accordance with the movement of the direct line moving member 30, and the drawing member 60 provided on the direct line moving member 30 can move in the shape of a quadratic curve.

[0035] Figure 7 is a diagram illustrating the process of drawing using the quadratic curve drawing device 1 of the present invention. First, the focus guide section 122 and the direct line guide section 126 are positioned using the scale 1022 attached to the frame 10.

[0036] After positioning the focus guide section 122 and the directrix guide section 126, hold the handle 32 and move the directrix moving member 30 to the position shown in Figure 7(a) to place and fix the quadratic curve drawing device 1 on the paper. In Figure 7, the top is the positive Y-axis direction and the right is the positive X-axis direction. If the fixing section 26 is the origin, then y = ax 2 It is possible to draw a quadratic curve.

[0037] After placing the quadratic curve drawing device 1 on the paper, the user grasps the handle 32 and moves the handle 32 in the positive X-axis direction as shown in Figure 7(b). At this time, the linear movement member 30 moves in the positive X-axis direction while maintaining its parallelism to the Y-axis. As the linear movement member 30 moves, the cross-shaped rotating member 20 rotates counterclockwise around the fixed part 26. At this time, the drawing member 60 of the linear movement member 30, which has the same rotating part 42 and wheel part 46 as the sliding member 40, moves the rail part 50 of the linear movement member 30 in conjunction with the movement of the sliding member 40 provided on the quadratic curve following part 22, drawing a downward curve until it passes approximately directly below the fixed part 26, with the point approximately directly below the fixed part 26 as the pole, and then drawing an upward quadratic curve. Furthermore, when the handle 32 is moved in the positive X-axis direction, it draws an even further upward curve as shown in Figure 7(c). In other words, the cross-shaped rotating member 20, which is connected to the linear moving member 30 and the sliding member 40, rotates around the fixed part 26 in conjunction with the movement of the linear moving member 30 in the X-axis direction, and the drawing member 60 draws a quadratic curve through the combined and cooperative motion of rotational movement and linear movement in the X-axis direction. [Examples]

[0038] Figure 8 shows the process of drawing quadratic curves with different rates of change by varying the spacing of the guide members 12. Before drawing, the size of the opening of the quadratic curve can be changed by changing the distance of the focus guide section 122 and the directrix guide section 126 from the central guide section 124 using the scale 1022 attached to the frame 10. Specifically, when drawing a quadratic curve using graph paper with 1 cm divisions, the scale 1022 is attached to one or both sides of the frame 10 at 1 cm intervals, with the fixed position of the central guide section 124 set to "0", increasing by "1" in the direction of the focus and the direction of the directrix. By positioning the focus guide section 122 and the directrix guide section 126 at the "1" mark on one or both sides of the frame 10, y=x 2 It is possible to draw a quadratic curve. Also, if the focus guide section 122 and the directrix guide section 126 are placed on the scale "2" on one or both sides of the frame 10, then y = (1 / 2)x 2 A quadratic curve can be drawn. When the distance of the focus guide section 122 and the directrix guide section 126 from the central guide section 124 is increased, the rotation angle of the cross-shaped rotating member 20 with respect to the rate at which the directrix moving member 30 moves in the positive X-axis direction decreases. That is, the rate at which the drawing member 60 moves in the Y-axis direction decreases, and therefore the rate at which the quadratic curve changes also decreases. Conversely, when the distance of the focus guide section 122 and the directrix guide section 126 from the central guide section 124 is decreased, the rotation angle of the cross-shaped rotating member 20 with respect to the rate at which the directrix moving member 30 moves in the positive X-axis direction increases. That is, the rate at which the drawing member 60 moves in the Y-axis direction increases, and therefore the rate at which the quadratic curve changes also increases.

[0039] In other words, the rate of change of the quadratic function can be determined based on the length of scale "1". For example, when drawing a quadratic curve using graph paper with a 1-inch scale, if scales 1022 are placed on one or both sides of the frame 10 at 1-inch intervals, and the focus guide section 122 and the directrix guide section 126 are placed on scales "1" on one or both sides, then y=x 2 It is possible to draw a quadratic curve. Also, by positioning the focus guide section 122 and the direct line guide section 126 on the scale "2" on one or both sides, y=(1 / 2)x can be drawn on graph paper with a 1-inch scale. 2It is possible to draw a quadratic curve of this magnitude.

[0040] Figure 9 shows a graph of a quadratic curve that can be drawn by changing the spacing of the guide members 12. Figure 9(a) corresponds to Figure 8(a), and Figure 9(b) corresponds to Figure 8(b). As shown in Figure 9, by positioning the focus guide 122 and the direct line guide 126 according to the scale 1022 attached to the frame 10, the user can easily and freely draw the quadratic curve they desire. In this embodiment and in the figures, the quadratic curve drawing device 1 is positioned so that the pole of the quadratic curve is at the origin for the sake of ease of explanation, but the pole can be changed to a position desired by the user by changing the position of the quadratic curve drawing device 1. [Industrial applicability]

[0041] The quadratic curve plotting tool according to the present invention can be used as teaching material to deepen understanding of quadratic functions in mathematics education in junior high and high schools. [Explanation of symbols]

[0042] 1. Quadratic curve drawing tool 10 Frame 102 First Frame 1022 divisions 104 Second Frame 12 Guide members 122 Focusing Guide Section 124 Central guide section 126 Line guide section 1262 Auxiliary guide section for the main line 128 Frame fixing part 14 Legs 16 Grounding part 20 Cross-shaped rotating member 22 Quadratic curve tracking section 222 Secondary curve tracking unit body 224 Slide support section 24 Arm 26 Fixed part 262 First layer fixed part 264 Second layer fixed part 266 Third layer fixed part 30 Linear moving member 32 Handles 40 Sliding member 42 Rotating part 44 Shaft section 46 Wheel section 50 Rail section 52 Rail stopper 60 drawing members DX directrix Parallel line to the X-axis passing through the PL focus

Claims

1. A parabola drawing device comprising a frame, a guide member, a cross-shaped rotating member, and a linear movement member, The frame, It consists of a first frame and a second frame, which are marked with scales at predetermined intervals and are arranged parallel to each other with a distance between the open ends of the parabola to be drawn. The guide member, It consists of a central guide section, a focus guide section, and a guide line section. The central guide section is It is spanned and fixed perpendicularly to the first frame and the second frame, The focus guide section and the line guide section are It is movable on the first frame and the second frame, and during drawing, it is stretched across and fixed to the first frame and the second frame at equal intervals from the central guide section. The cross-shaped rotating member, It consists of a quadratic curve tracking section and an arm section, and with the quadratic curve tracking section and the arm section maintaining a vertical position, the arm section is rotatably fixed by a fixing section at approximately the center of the arm section at a position approximately equidistant from the first and second frames on the central guide section, and the arm section and the focus guide section, and the arm section and the direct line guide section are rotatably and slidably connected at their intersections. The linear moving member is While maintaining parallelism with the frame, the drawing member is rotatably and slidably connected to the direct line moving member at the intersection with the quadratic curve tracking member from the central guide section to the focus guide section, and is slidably connected to the direct line guide section from the central guide section to the direct line guide section, A parabola drawing device characterized by moving the guideline length in the handed direction, causing the drawing member to draw a parabola on the paper.

2. The quadratic curve tracking section is To avoid interfering with the movement of the drawing member that traces a parabola, the rotation axis in the fixed part and the part on which the drawing member slides are configured in two layers. A parabola plotter according to claim 1, characterized by the following:

3. The focus guide section and the line guide section are By changing the distance from the central guide while maintaining a constant distance from the central guide and fixing it to the frame, the size of the opening in the drawn parabola is changed. A parabola plotter according to claim 1 or claim 2, characterized by the above.

Images