CN2229358Y - Two-hole constant value line protractor compass - Google Patents

Abstract

The utility model discloses a two-hole constant value line protractor compass. A fixed point hole is arranged on the center of the circle of a protractor, and is the 0 point of the two-hole constant value line. Series moving point holes are arranged on ten angular lines, and the two-hole constant value line can be assembled by any moving point hole and the fixed point hole. The values are all different, and a hollow rivet or a screw is installed in the fixed point hole. When the drawing is conducted, the hollow rivet or the screw is pressed by the fingers of a hand, or a thumbtack is pressed in the hole. The fixed point hole becomes a shaft center, and the protractor can be rotated around the shaft. A ball pen or a pencil, a chromatic nylon pen and a chalk are inserted in the moving point holes; the pens arranged in the moving point holes are moved; the protractor is rotated; an arc and a circumference is colored and drawn. The utility model is suitable for doing exercises and drawing geometrical figures by students, using as a teaching aid by teachers, and plotting chart images by engineering and general personnel.

Description

Two hole definite value line protractor compasses

The utility model relates to the structure of compasses, the structure of protractor, and compasses and protractor are combined into a device.

The machinery compasses are 2 constant value lines structures, need use the protractor angulation, and with number dipstick metering constant value line length, the colouring of drawing need to more move and locate nib, finishes these operations and could draw afterwards.Therefore, function is few, and flow chart is many, and efficient is low.Protractor can only angulation, function singleness.Improve the shortcoming that compasses and protractor exist, gesture is being combined into a device to compasses and protractor, is its good plan.

Improve circular protractor and in-line protractor, make it to have the function of compasses, be both are combined into a device.The fixed point hole is set on the protractor center of circle, by dress tubular rivet or screw, with a finger, pins fixed point hole hollow core rivet or tired silk during drawing in the hole.Perhaps, in the fixed point hole, be pressed into drawing pin.Make the fixed point hole become the axle center, protractor can rotate around the axis.The moving point of series hole is set on the protractor linea angulata, with any one moving some hole and fixed point hole, makes up two hole definite value lines, its value is all different.The pen that inserts in the moving some hole of mobile two hole constant value lines, the amount of spin hornwork is drawn circular arc or circumference.

The purpose of this utility model is that a kind of two hole definite value line protractor compasses will be provided, and it can be effectively for the student does one's assignment, and the teacher is at the teaching aid of draw circles on the blackboard or on the blank and circular arc, this one.Its two, allow common people know, the definition of circle: 2 constant value line compasses only can justifys, and two hole constant value line protractor compass both can justifys, the part arc length during also amount usable hornwork work is justified.Therefore, should enrich the content to round definition,

The utility model is to realize like this.With the fixed point hole on the protractor, as 0 point of two hole constant value lines.With the moving point of the series on ten linea angulatas of protractor hole and fixed point hole, make up two hole constant value lines.The pitch-row in moving some hole is 10 millimeters of constants on each linea angulata, consists of the arithmetic progression pitch-row.Article ten, on the linea angulata with the protractor center of circle on an adjacent moving some hole, fixed point hole, make up the units of two hole constant value lines, consist of 0～90 numeral.This just makes the numerical value of combination two hole constant value lines not identical, can move the pen in the moving some hole for being elected to be sweep, and the amount of spin hornwork is drawn circular arc or circumference.

Compasses and protractor are combined into a device two kinds of structures: the circular protractor compasses of two hole definite value lines; Two hole definite value line in-line protractor compasses.The former protractor is the radius linea angulata, and linea angulata is isometric.The latter is the ray linea angulata, and adjacent linea angulata is not isometric.As two tangent lines, short linea angulata can be prolonged it with two ray linea angulata draw circles heart angles.

Aperture, fixed point hole commonly used is 3～5 millimeters, with the finger of proficiency, pins and decides hole hollow core rivet or screw during drawing, perhaps, is pressed into drawing pin in the fixed point hole.The aperture, fixed point hole of using on the blackboard is 6～8 millimeters.By dress tubular rivet or screw, with the finger of proficiency, pin fixed point hole hollow core rivet or screw during drawing in the hole.Decide according to inserting written rugosity in moving some aperture, hole, multi-color ballpoint pen, pencil, colored nylon pen commonly used, and written rugosity is 1.5～2 millimeters, so moving some aperture, hole is with 2 millimeters.The moving some hole of using on the blackboard, owing to insert chalk in the hole, so the aperture is with 12～14 millimeters.

Drafting method.Earlier the center of circle and central angle, the origin of curve and terminal point are being set on the drawing or on the blackboard with protractor.Thereafter be pressed on the center of circle with fixed point hole on the protractor, on the tubular rivet or screw by dress in the hole, the finger of using proficiency is by it.Fixed two hole constant value lines are pressed on the known tangent line, the pen in the mobile moving some hole, the amount of spin hornwork ends to another known tangent line, draws circular arc.If two hole constant value lines are rotated a week, can paint circumference.

The utility model is applicable to the operation of student's doing mathematics, and drawing geometric figures is made stationery and used.The teacher is drawing geometric figures on blackboard, makes teaching aid and uses.Engineers and technicians and general staff, curve plotting figure, the instrument of doing uses.

The utility model is existing two point form machinery compasses, increases a kind of twoport type on-mechanical compasses, and structure is very simple; Along with stylographic development, of a great variety, multi-color ballpoint pen is wherein arranged, the colored nylon pen, all can be used as the colouring drawing pen usefulness, the efficient height; One device multipotency has high economic benefit and social benefit.

The concrete structure of the utility model is provided by following examples and accompanying drawing.

Fig. 1 is the circular protractor compasses of two hole definite value lines.The hole (1) of fixing a point on the protractor among the figure, hole hollow core rivet or screw are pinned with the finger of proficiency during drawing in 3～5 millimeters in aperture.Perhaps, in the fixed point hole, be pressed into drawing pin.Except fixed point hole (1), each hole is moving some hole, 2 millimeters in aperture among the figure.The two hole constant value lines of Fig. 1 have more than 30, and each value is all not identical, can be elected to be sweep, draws circular arc or circumference.Moving some hole (3 and 4), use in the fixed point hole in the non-center of circle of double as respectively, is pressed into drawing pin in the hole, becomes the axle center, and protractor rotates with this axle center.12 and 13 millimeters constant value line is made up respectively in it and moving some hole (2 and 5), and this is because be difficult to arrange the event of these two kinds of constant value lines among the figure.When fixed point is pressed into drawing pin in the hole, should be chart board below the drawing, perhaps fill up the hardboard of lastblock file type size, be convenient to drawing pin and be pressed into.Fig. 1 can be located on the chi limit of set square, and each linea angulata among the figure should extend on other two chis limit.Radius increase along with Fig. 1 is beneficial to increasing of two hole definite value line numbers.

Fig. 2 is two hole definite value line in-line protractor compasses.Fixed point hole (1) is set on the protractor center of circle among the figure, and hole hollow core rivet or screw with the finger of proficiency, are pinned during drawing in 3～5 millimeters in aperture.Perhaps, in the fixed point hole, be pressed into drawing pin.Except fixed point hole (1), other each hole is moving some hole, 2 millimeters in aperture among Fig. 2.Nearly 70 of two hole definite value lines are made up in the fixed point Kong Yudong point hole of Fig. 2, and each numerical value is all inequality, and the optional curve radius of doing is drawn circular arc or circumference.Use in the fixed point hole in the moving point non-center of circle of double as, hole (3 and 4), is pressed into drawing pin in the hole.12 and 13 millimeter two hole constant value line made up respectively in it and moving some hole (2 and 5), and this is because be difficult to arrange the event of these two kinds of constant value lines among Fig. 2.Some circumference are set among Fig. 2, are to be used for drawing because Fig. 2 is difficult to arrange the minor radius circle.Fig. 2 can be extended for 30,40,50 ... 100 centimeters, wherein 50 and 60 centimeters length can be done the teaching aid use on the blackboard.But the aperture in the hole (1) of fixing a point among Fig. 2 should change 6～8 millimeters into, owing to insert the chalk mapping in the moving some hole, precision is lower, so only on 0 ° of linea angulata of the fixed point left and right sides, hole (1), the moving point of series hole is set, can uses mapping, 12～14 millimeters in aperture.According to said method change, can make teaching aid, draw circular arc or circumference.Fig. 2 can be located on the chi limit of set square, and the linea angulata among the figure should extend on other two chis limit.Length lengthening along with Fig. 2 is beneficial to two hole definite value line numbers and increases thereupon.

Claims (1)

1, a kind of two hole constant value line protractor compass is characterized in that: on circular protractor and the in-line protractor, at its circle centre position the fixed point hole is set, as 0 point of two hole constant value lines; Article ten, the moving point of series hole is set on the linea angulata, and each moving some hole pitch-row is 10 millimeters of constants on every linea angulata, consists of the pitch-row of arithmetic progression; Article ten, on every linea angulata of linea angulata, the constant value line of the moving some hole combination adjacent with the fixed point hole, its units consists of 0～90 numeral, thereby with any one moving some hole and fixed point hole, the numerical value that makes up two hole constant value lines is all not identical; By dress tubular rivet or screw, perhaps be pressed into drawing pin in the fixed point hole.

Images