CN211031930U

CN211031930U - Ellipse diagraph teaching aid for blackboard

Info

Publication number: CN211031930U
Application number: CN201922138954.XU
Authority: CN
Inventors: 黄会芸; 陈辽军; 唐晓莲
Original assignee: Nanjing Polytechnic Institute
Current assignee: Nanjing Polytechnic Institute
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2020-07-17
Anticipated expiration: 2029-12-03

Abstract

In mathematical education, different ellipses are often required to be drawn on a blackboard, approximate ellipses are drawn by hands, and the drawing lines are inaccurate, unsmooth and hard to see. The existing cross-shaped slider type ellipsograph is adopted to draw an ellipse, although the ellipse can be drawn accurately and smoothly, when the ellipse is operated on a blackboard by a single person, the operation is inconvenient, and the drawing principle and the parameter transformation of the cross-shaped slider type ellipsograph are not visual. An ellipse drawing instrument teaching aid for a blackboard achieves the purpose of drawing an ellipse with an adjustable parameter range by utilizing the principle that the sum of the distances from a chalk to two fixed points is controlled to be constant by a thread rope.

Description

Ellipse diagraph teaching aid for blackboard

(I) technical field

The utility model belongs to a teaching aid for slow accurate oval purpose on the blackboard.

(II) background of the invention

In mathematical education, different ellipses are often required to be drawn on a blackboard, approximate ellipses are drawn by hands, and the drawing lines are inaccurate, unsmooth and hard to see. The existing cross-shaped slider type ellipsograph is adopted to draw an ellipse, although the ellipse can be drawn accurately and smoothly, when the ellipse is operated on a blackboard by a single person, the operation is inconvenient, and the drawing principle and the parameter transformation of the cross-shaped slider type ellipsograph are not visual.

Disclosure of the invention

The utility model discloses the technical scheme who solves above-mentioned technical problem and adopt is realized like this: the method achieves the purpose of drawing an ellipse with an adjustable parameter range by utilizing the principle that the sum of the distances from a chalk to two fixed points is constant under the control of a cord, and is characterized in that: t-shaped grooves are formed in the upper portion and the lower portion of the bottom plate, magnetic stripes are embedded in the lower T-shaped grooves, the whole bottom plate can be adsorbed on the color-coated steel blackboard, two sliding blocks are arranged in the T-shaped grooves in the upper portion of the bottom plate, the distance of the sliding blocks can be changed by moving along the axial direction of the grooves, the sliding blocks are provided with threaded holes, hand-screwing screws with holes are connected with the threaded holes, a thread rope penetrates through the holes of the screws on the two sides and comes out of the thread grooves; the chalk holder is characterized in that an annular groove is formed in the middle of the chalk holder, a wire rope is sleeved in the groove and cannot move up and down, the lower portion of the chalk holder is of a hollow structure and used for inserting chalk, four grooves are formed in the periphery of the hollow structure for fixing the chalk, the outer portion of the hollow structure is of an inverted cone shape and provided with a hoop, and the hoop is pushed downwards to enable the hollow structure to be contracted inwards to clamp the chalk; when the chalk is used for drawing an ellipse, the rope is sleeved in the annular groove of the chalk holder, the chalk holder is moved while the rope is always in a tensioned state, and the chalk can draw a designated ellipse on the blackboard.

(IV) description of the drawings

Fig. 1 is a schematic structural diagram of an ellipse diagraph teaching aid for a blackboard.

Fig. 2 is an exploded view of an ellipse mapper teaching aid for a blackboard.

In fig. 1 and 2: 1-magnetic strip; 2-a bottom plate; 3-left slider; 4, screwing the screw with the left hole; 5-a wire rope; 6-hand screw with right hole; 7-right slider; and 8, a chalk holder.

Fig. 3 is a schematic structural view of a chalk holder.

Fig. 4 is an exploded view of a chalk holder.

In fig. 3 and 4: 801-pen shaft; 802 — a ferrule; 803-chalk.

(V) detailed description of the preferred embodiments

The technical scheme of the ellipse diagraph teaching aid for the blackboard of the utility model is further explained with the accompanying drawings as follows: the method achieves the purpose of drawing an ellipse with an adjustable parameter range by utilizing the principle that the sum of the distances from a chalk to two fixed points is constant under the control of a cord, and is characterized in that: the upper and lower of bottom plate 2 is opened there is T type groove, the T type groove embedding magnetic stripe 1 of lower part, adsorbable on the color-coated steel blackboard, thereby there are left slider 3 and right slider 7 in the T type groove on upper portion to make axial displacement along the groove and can change the distance between the two sliders, left slider 3, right slider 7 has the screw hole, left foraminiferous hand is twisted spiral shell 4 and right foraminiferous hand and is twisted spiral shell 6 and connect on it respectively, cotton rope 5 passes the hole of two screws and follows left slider 3, the wire casing of right slider lower part comes out, it locks the cotton rope when the screw can fix a position the slider to tighten, loosen the movable slider of two screws and change the distance and pull the length that the. The bottom plate 2 is provided with scales, and the two sliding blocks are provided with positioning lines which can measure the moving distance of the two sliding blocks. The middle part of the chalk holder 8 is provided with an annular groove, the wire rope is sleeved in the groove and cannot move up and down, the lower part of the chalk holder is of a hollow structure and is used for inserting chalk, four grooves are formed in the periphery of the hollow structure for fixing the chalk, the outer part of the hollow structure is of an inverted cone shape, the hoop 802 is arranged on the hollow structure, the hoop 802 is pushed downwards, the hollow structure is retracted, and the chalk 803 is clamped. When the chalk is used for drawing an ellipse, the rope is sleeved in the annular groove of the chalk holder, the chalk holder is moved while the rope is always in a tensioned state, and the chalk can draw a designated ellipse on the blackboard.

Claims

1. The utility model provides an ellipse diagraph teaching aid for blackboard, utilizes the cotton rope control chalk to reach the purpose of drawing the ellipse of certain parameter range adjustable to the principle that two fixed point distance sums are invariable, characterized by: t-shaped grooves are formed in the upper portion and the lower portion of the bottom plate, magnetic stripes are embedded in the lower T-shaped grooves, the whole bottom plate can be adsorbed on the color-coated steel blackboard, two sliding blocks are arranged in the T-shaped grooves in the upper portion of the bottom plate, the distance of the sliding blocks can be changed by moving along the axial direction of the grooves, the sliding blocks are provided with threaded holes, hand-screwing screws with holes are connected with the threaded holes, a thread rope penetrates through the holes of the screws on the two sides and comes out of the thread grooves; the chalk holder is characterized in that an annular groove is formed in the middle of the chalk holder, a wire rope is sleeved in the groove and cannot move up and down, the lower portion of the chalk holder is of a hollow structure and used for inserting chalk, four grooves are formed in the periphery of the hollow structure for fixing the chalk, the outer portion of the hollow structure is of an inverted cone shape and provided with a hoop, and the hoop is pushed downwards to enable the hollow structure to be contracted inwards to clamp the chalk; when the chalk is used for drawing an ellipse, the rope is sleeved in the annular groove of the chalk holder, the chalk holder is moved while the rope is always in a tensioned state, and the chalk can draw a designated ellipse on the blackboard.