CN108215594B

CN108215594B - Multifunctional ruler

Info

Publication number: CN108215594B
Application number: CN201810042765.XA
Authority: CN
Inventors: 董勇; 阿克交力·克外; 尹兰
Original assignee: Hunan Institute of Technology
Current assignee: Hunan Institute of Technology
Priority date: 2018-01-17
Filing date: 2018-01-17
Publication date: 2020-07-28
Anticipated expiration: 2038-01-17
Also published as: CN108215594A

Abstract

The invention provides a multifunctional ruler, which comprises two ruler bodies, two guide rails arranged on the inner sides of the ruler bodies, a first slide block and a second slide block, wherein the first slide block is fixed at the left end of the guide rails, a positioning nail capable of being pressed is arranged on the first slide block, the end part of the positioning nail can extend out of the bottom of the ruler body by pressing, the second slide block is positioned on the right side of the first slide block, a screw rod is connected with the second slide block in a threaded manner, the top end of the screw rod is connected with an angle measuring disc, the bottom end of the screw rod is connected with a pen core, the ruler body also comprises two fixing parts, one fixing part is used for fastening the left ends of the two ruler bodies together, the other fixing part is used for fastening the right ends of the two ruler bodies together, scale lines for measuring the length are marked on the ruler bodies, scale lines for measuring the angle are marked on the upper surface of the angle measuring, the ruler body, the second sliding block, the guide rail and the angle measuring disc are all made of transparent plastics.

Description

Multifunctional ruler

Technical Field

The invention relates to the technical field of surveying and mapping tools, in particular to a multifunctional ruler.

Background

For teachers and mappers, rulers, isosceles right-angle triangular rulers, compasses, protractors and the like are commonly used surveying and mapping tools which are independent of each other and different in function, wherein the rulers are used for measuring the length of straight lines and drawing straight lines, the compasses are used for drawing circles, and the protractors are used for measuring included angles and assisting in drawing specific included angles. In the actual use process, teachers or mappers usually need to carry all the tools in order to completely and normally map out ideal figures, and the operation is very inconvenient.

At present, technical personnel in the industry improve a common ruler, a part of the ruler can draw a straight line and a circle according to the use requirements of users, size positioning processing and length measurement can also be carried out, certain convenience is brought to the users, but the functions of the ruler are still few, included angles in a plane or the gradient of the plane cannot be measured, and the structure is complex.

Disclosure of Invention

The multifunctional ruler provided by the invention has the advantages of multiple functions, simple structure and convenience in installation.

In order to solve the technical problems, the invention adopts the following technical scheme: a multifunctional ruler comprises two ruler bodies, wherein the two ruler bodies are oppositely arranged, the opposite inner sides of the two ruler bodies are transversely provided with a guide rail respectively, the two guide rails are connected with a first sliding block and a second sliding block in a sliding manner, the top of the first sliding block is connected with a clamping hook capable of preventing the first sliding block from sliding relative to the guide rails, the upper surface of one ruler body is provided with a groove, a hook at the tail end of the clamping hook is inserted into the groove, a through hole is downwards formed in the top end of the first sliding block, a positioning nail is arranged in the through hole, the tail end of the positioning nail is positioned between the two ruler bodies, a first spring is sleeved on the positioning nail, the upper end and the lower end of the first spring are respectively connected with the top of the positioning nail and the upper surface of the first sliding block, and the end of the positioning nail can extend out of the bottom of the ruler body by, the second slider is positioned on the right side of the first slider, a threaded hole is formed from the top end to the bottom end of the second slider, a screw rod is assembled in the threaded hole, the top end of the screw rod is fixedly connected with an angle measuring disc positioned above the ruler bodies, the bottom end of the screw rod is connected with a pen core, the ruler bodies further comprise two fixing parts, one fixing part is used for fastening the left ends of the two ruler bodies together, the other fixing part is used for fastening the right ends of the two ruler bodies together, scale marks for measuring length are marked on the ruler bodies, scale marks for measuring angle are marked on the upper surface of the angle measuring disc, transparent colored liquid with half volume is further packaged in the angle measuring disc, the ruler bodies, the second slider, the guide rails and the angle measuring disc are all made of transparent plastics, and when the pen core is required to draw a figure, the pen point of the pen core can be screwed out from the bottom of the ruler body by rotating the angle measuring disc, and the angle measuring disc is tightly attached to the upper surface of the ruler body at the moment.

Further, the left end of two ruler bodies all is equipped with left boss, is located the mounting of ruler body left end is for only seting up the left boss upper shield of a fixed slot, and two left boss chucking are fixed in the fixed slot of left boss upper shield, the right-hand member of two ruler bodies all is equipped with right boss, is located the mounting of ruler body right-hand member is for seting up the right boss upper shield of two fixed slots, and two right bosses are fastened respectively and are fixed in two fixed slots of right boss upper shield.

Furthermore, the upper and lower surface of left side boss upper shield all with the upper and lower surface parallel and level of ruler body, the upper and lower surface of right side boss upper shield all with the upper and lower surface parallel and level of ruler body, the preceding, the back both sides of left side boss upper shield all with the preceding, the back both sides parallel and level of ruler body respectively, the preceding, the back both sides of right side boss upper shield all with the preceding, the back both sides parallel and level of ruler body respectively.

Furthermore, a second spring is sleeved on the screw rod, and the upper end and the lower end of the second spring are respectively abutted against the lower surface of the angle measuring disc and the upper surface of the guide rail.

And furthermore, a clamping groove is formed in the bottom of the screw rod, and the refill is detachably arranged in the clamping groove of the screw rod.

Still further, the bottom of screw rod fixedly connected with a snap ring, refill detachable installs in the snap ring.

Furthermore, the hook is made of a spring steel wire.

Furthermore, the scale mark of one of them ruler body marks in the inward flange of this ruler body, and the scale mark of another ruler body marks in the outward flange of this ruler body, the scale mark of angle measurement dish marks in the edge of angle measurement dish upper surface, just 0 scale mark and 90 scale marks of angle measurement dish all extend to the central point of angle measurement dish from the edge of angle measurement dish, and work as when the angle measurement dish hugs closely in the ruler body, 0 scale mark is on a parallel with the long limit of ruler body.

Preferably, the positioning nails are located at the zero scale lines of the ruler body, the top of the positioning nails is fixedly connected with a rotary disc which is convenient to rotate, and the rotary disc is located above the ruler body.

The multifunctional ruler provided by the invention can realize various surveying and mapping functions, can measure and draw a straight line, has the same using method as a common ruler, is placed on a surveying and mapping surface, and is drawn along the edge of the ruler body by using a painting brush; secondly, drawing a circle can be achieved by replacing compasses, the distance between the positioning nail and the refill is ensured to be equal to the radius of the circle when the circle is drawn, then the lower surface of the ruler body is tightly attached to the upper surface of the ruler body by rotating the angle measuring disc, the pen point of the refill extends out of the ruler body, finally the positioning nail is pressed downwards to be abutted against a surveying and mapping surface, and the ruler body is rotated for a circle; thirdly, since the angle measuring disc is marked with scale marks for measuring angles, and the ruler body, the second slide block, the guide rail and the angle measuring disc are all made of transparent plastics, the angle measuring disc can replace a protractor to measure and draw angles; fourthly, in some engineering measurement fields, a surveying and mapping engineer needs to measure an included angle between a certain plane and a horizontal plane, namely the inclination of the plane, the measuring function can be realized, when in measurement, an angle measuring disc is adjusted firstly to enable a 0-degree scale mark to be parallel to a long edge of a ruler body, then the ruler is vertically placed on the plane to enable the long edge of the ruler body to be tightly attached to the plane, and finally the inclination of the plane can be obtained by observing the scale mark pointed by the liquid level in the angle measuring disc.

From the above, the ruler, the compasses and the protractor are convenient to operate, have various functions, and ingeniously realize the integration of various independent surveying and mapping tools of the ruler, the compasses and the protractor. Moreover, the multifunctional ruler provided by the invention has the advantages of simple structure, low cost, convenience in disassembly and assembly, convenience in mass production in factories and convenience for users to maintain and clean the ruler. In addition, the multifunctional ruler is reasonable in structural design, when the multifunctional ruler is not needed, the positioning nails and the pen cores are stored between the two ruler bodies, a user can be prevented from being scratched by the positioning nails, and the positioning nails and the pen cores can be prevented from being broken and damaged.

Drawings

Fig. 1 is a schematic overall structure diagram of the multifunctional ruler in the invention;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

FIG. 3 is a cross-sectional view taken along line B-B of FIG. 1;

FIG. 4 is a schematic view of the multifunctional straightedge of the present invention with the fasteners removed;

fig. 5 is a schematic structural view of the left boss cover in the present invention.

Fig. 6 is a schematic structural view of the right boss cover in the present invention.

Fig. 7 is a schematic structural view of the angle measuring disk of the present invention.

The reference signs are:

1-ruler body 2-guide rail 3-first slide block

4-second slide block 5-hook 6-groove

7-positioning nail 8-first spring 9-screw

10-angle measuring disc 11-pen core 12-coloured liquid

13-left boss 14-left boss cover 15-right boss

16-right boss cover 17-second spring 18-rotary disc

10 a-0 degree scale mark 10 b-90 degree scale mark.

Detailed Description

In order to facilitate understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, mechanically or electrically connected, or interconnected between two elements, directly or indirectly through intervening media, and the specific meaning of the terms may be understood by those skilled in the art according to their specific situation.

As shown in fig. 1-7, a multifunctional ruler comprises two ruler bodies 1, wherein the two ruler bodies 1 are arranged oppositely, and the inner sides of the two ruler bodies 1 opposite to each other are respectively and transversely provided with a guide rail 2, the two guide rails 2 are connected with a first slider 3 and a second slider 4 in a sliding manner, the top of the first slider 3 is connected with a hook 5 capable of preventing the first slider 3 from sliding relative to the guide rails 2, a groove 6 is formed in the upper surface of one ruler body 1, a hook at the tail end of the hook 5 is inserted into the groove 6, a through hole is formed downwards from the top end of the first slider 3, a positioning nail 7 is arranged in the through hole, the tail end of the positioning nail 7 is positioned between the two ruler bodies 1, a first spring 8 is sleeved on the positioning nail 7, the upper end and the lower end of the first spring 8 are respectively connected with the top of the positioning nail 7 and the upper surface of the first slider 3, and when the positioning nail 7 is pressed by a finger, the positioning nail 7 can move downwards in the through hole, so The bottom of body 1 stretches out, first spring 8 is compressed this moment, leave location nail 7 with the finger pine after that, under the effect of stretching of first spring 8, location nail 7 resumes the normal position, the tip of location nail 7 is collected between two ruler bodies 1, when using this embodiment to draw the circle, will adopt location nail 7 as the centre of a circle position of waiting to draw the circle, in order to make location nail 7 can realize better fixed point function (centre of a circle position is not movable), the end of location nail 7 can be for sharp column structure, this location nail 7's overall structure designs very rationally: not only can play a good role in positioning, but also can effectively prevent the positioning nail 7 from scratching a user, and improve the use safety; the second slider 4 is positioned on the right side of the first slider 3, a threaded hole is formed from the top end to the bottom end of the second slider 4, a screw rod 9 is assembled in the threaded hole, the top end of the screw rod 9 is fixedly connected with an angle measuring disc 10 positioned above the ruler bodies 1, the bottom end of the screw rod 9 is connected with a pen core 11, the ruler bodies 1 further comprise two fixing parts, one fixing part is used for fastening the left ends of the two ruler bodies 1 together, the other fixing part is used for fastening the right ends of the two ruler bodies 1 together, scale marks for measuring length are marked on the ruler bodies 1 (the scale mark range is determined according to actual conditions), scale marks for measuring angles are marked on the upper surface of the angle measuring disc 10 (the upper half circle of the angle measuring disc 10 is marked with 0-180 degrees in the anticlockwise direction, and the lower half circle of the angle measuring disc 10 is marked with 0-180 degrees in the clockwise, the angle measuring disc 10 is also internally packaged with a half volume of transparent colored liquid 12, the colored liquid 12 can be kept in a horizontal state in the angle measuring disc 10 all the time under the action of gravity, so that if the angle measuring disc 10 is vertically placed to rotate, the scale marks pointed by the liquid level of the colored liquid 12 are different, and the ruler body 1, the second slider 4, the guide rail 2 and the angle measuring disc 10 are made of transparent plastics, so that the angle of a figure below the ruler body 1 can be measured by using the angle measuring disc 10; when the pen core 11 is needed to draw a circle, the pen point of the pen core 11 can be screwed out from the bottom of the ruler body 1 through the rotation angle measuring disc 10, and the angle measuring disc 10 is tightly attached to the upper surface of the ruler body 1, so that the second sliding block 4 can be effectively prevented from sliding on the guide rail 2, and the distance between the pen core 11 and the positioning nail 7 can be kept unchanged.

The working principle of the multifunctional ruler provided by the above embodiment is as follows:

1. drawing a straight line: the use method is the same as that of a common ruler, the multifunctional ruler is placed on a mapping plane (a blackboard, a drawing board and the like are represented by the following mapping plane) and then a painting brush is used for drawing along the edge of the ruler body 1; the method for measuring the straight line is the same as that of a common ruler;

2. drawing a circle: firstly, sliding the angle measuring disc 10 to ensure that the distance between the positioning nail 7 and the pen core 11 is equal to the radius of a circle to be drawn, then rotating the angle measuring disc 10 to enable the lower surface of the angle measuring disc to be tightly attached to the upper surface of the ruler body 1, enabling the pen point of the pen core 7 to extend out of the bottom of the ruler body 1 and to be in contact with a surveying and mapping plane, finally pressing the positioning nail 7 downwards to enable the positioning nail 7 to be abutted against the surveying and mapping plane, and rotating the ruler body 1 for a;

3. measuring and drawing angles: because the angle measuring disc 10 is marked with scale lines for measuring angles, and the ruler body 1, the second slide block 4, the guide rail 2 and the angle measuring disc 10 are all made of transparent plastics, the angle measuring disc 10 can replace a protractor to measure and draw angles, and the using method of the angle measuring disc is the same as that of the protractor;

4. measuring the plane inclination: in some engineering measurement fields, the surveying and mapping engineer need measure the contained angle between certain plane and the horizontal plane, also this planar gradient, this multi-functional ruler can realize this measurement function, during the measurement, adjust angle measuring disc 10 earlier and make its 0 scale mark 10a be on a parallel with the long limit of ruler body 1, place this multi-functional ruler perpendicularly again on the plane and make the long limit of its ruler body 1 hug closely in the plane, the directional scale mark change of coloured liquid 12 liquid level can learn this planar gradient through observing angle measuring disc 10 in the end. Such as: when the multifunctional ruler is placed on a horizontal plane, the liquid level of the colored liquid 12 in the angle measuring disc 10 points to the 0-degree scale mark, the multifunctional ruler is placed on an inclined plane according to the method, the liquid level of the colored liquid 12 in the angle measuring disc 10 points to the 30-degree scale mark, and the inclination angle of the plane relative to the horizontal plane is 30 degrees.

From the top, this embodiment's a multi-functional ruler simple operation, the function is various, ingenious realization to the integration of ruler, compasses and the multiple independent mapping tool of protractor. Moreover, the multifunctional ruler provided by the embodiment has the advantages of simple structure, low cost, convenience in installation and convenience for mass production of factories. In addition, the multifunctional ruler has reasonable structural design, and when the multifunctional ruler is not needed to be used, the positioning nails 7 and the pen cores 11 are all collected between the two ruler bodies 1, so that a user can be prevented from being scratched by the positioning nails 7, and the positioning nails 7 and the pen cores 11 can be prevented from being broken and damaged.

Consider that above-mentioned multi-functional ruler live time has been of a specified duration and can have accumulated the dust, for the convenience of cleaning, further, as shown in fig. 1, 4, 5, 6, two left ends of ruler body 1 all are equipped with left boss 13, the mounting that is located the 1 left end of ruler body is the left boss upper shield 14 of only seting up a fixed slot, two left boss 13 chunkings are fixed in the fixed slot of left boss upper shield 14, in this fixed slot, it is gapped between two left bosses 13, the benefit of seting up a fixed slot lies in: the two left bosses 13 can be effectively fixed together, and when the multifunctional ruler needs to be cleaned, the left boss sleeve cover 14 can be easily taken out of the ruler body 1 by only pulling the hook 5 on the first sliding block 3 out of the groove 6, sliding the first sliding block 3 and the second sliding block 4 to the right end of the guide rail 2 and finally squeezing the two left bosses 13 towards the middle by hands, so that the multifunctional ruler is disassembled, and the multifunctional ruler is very quick and convenient to clean; and the right-hand member of two ruler bodies 1 all is equipped with right boss 15, and the mounting that is located the right-hand member of ruler body 1 is for offering the right boss upper shield 16 of two fixed slots, and two right bosses 15 chucking respectively are fixed in two fixed slots of right boss upper shield 16, also a fixed right boss 15 of fixed slot, and the chucking of the right boss upper shield 16 of this kind of structure is fixed effectually.

Still further, as shown in fig. 1, the upper and lower surfaces of the left boss sleeve cover 14 are all flush with the upper and lower surfaces of the ruler body 1, the upper and lower surfaces of the right boss sleeve cover 16 are all flush with the upper and lower surfaces of the ruler body 1, the front and rear sides of the left boss sleeve cover 14 are respectively flush with the front and rear sides of the ruler body 1, the front and rear sides of the right boss sleeve cover 16 are respectively flush with the front and rear sides of the ruler body 1, and the multifunctional ruler with such a structure is very attractive.

In order to make the connection between the screw 9 and the guide rail 2 more firm, as shown in fig. 3, a second spring 17 is sleeved on the screw 9, and the upper end and the lower end of the second spring 17 respectively abut against the lower surface of the angle measuring plate 10 and the upper surface of the guide rail 2.

In consideration of convenience in replacing the refill 11, the bottom of the screw rod 9 is further provided with a clamping groove, and the refill 11 is detachably arranged in the clamping groove of the screw rod 9; or the bottom of the screw rod 9 is fixedly connected with a snap ring, and the pen core 11 is detachably arranged in the snap ring.

Still further, pothook 5 adopts the spring steel wire preparation to form, and 5 terminal hooks of pothook are inserted in recess 6, because the spring steel wire has certain bendability, consequently when this multi-functional ruler of needs dismouting, can use tools take out 5 terminal hooks of pothook from the perk in recess 6 to first slider 3 can slide on guide rail 2, subsequent dismouting work of being convenient for.

Still further, the scale mark of one of the ruler bodies 1 is marked on the inner edge of the ruler body 1, so that the distance between the positioning nail 7 and the pen core 11 is determined when a circle is drawn conveniently, namely the radius of the circle to be drawn is also determined, and the scale mark of the other ruler body 1 is marked on the outer edge of the ruler body 1, so that the length value is determined when a straight line is drawn conveniently. The scale mark of angle measurement dish 10 marks in the edge of angle measurement dish 10 upper surface, 0 scale mark 10a and 90 scale mark 10b of angle measurement dish 10 all extend to the central point of angle measurement dish 10 from the edge of angle measurement dish 10, and when angle measurement dish 10 hugs closely in ruler body 1, 0 scale mark 10a is on a parallel with the long limit of ruler body 1, so, when measuring planar gradient, the contained angle between 0 scale mark of angle measurement dish 10 and the directional scale mark of liquid level is plane gradient promptly.

Preferably, the positioning nails 7 are located at the zero graduation lines of the ruler body 1, the top of the positioning nails 7 is fixedly connected with a turntable 18 which is convenient to rotate, and the turntable 18 is located above the ruler body 1.

The above embodiments are preferred implementations of the present invention, and the present invention can be implemented in other ways without departing from the spirit of the present invention.

Some of the drawings and descriptions of the present invention have been simplified to facilitate the understanding of the improvements over the prior art by those skilled in the art, and some other elements have been omitted from this document for the sake of clarity, and it should be appreciated by those skilled in the art that such omitted elements may also constitute the subject matter of the present invention.

Claims

1. A multifunctional ruler is characterized in that: comprises two ruler bodies (1), wherein the two ruler bodies (1) are arranged oppositely, the inner sides of the two ruler bodies (1) which are opposite are respectively and transversely provided with a guide rail (2), the two guide rails (2) are connected with a first sliding block (3) and a second sliding block (4) in a sliding way, the top of the first sliding block (3) is connected with a hook (5) which can prevent the first sliding block (3) from sliding relative to the guide rails (2), the upper surface of one ruler body (1) is provided with a groove (6), the hook at the tail end of the hook (5) is inserted into the groove (6), a through hole is downwards formed in the top end of the first sliding block (3), a positioning nail (7) is arranged in the through hole, the tail end of the positioning nail (7) is positioned between the two ruler bodies (1), the positioning nail (7) is sleeved with a first spring (8), the upper end and the lower end of the first spring (8) are respectively connected with the top of the positioning nail (7) and the upper surface of the first slider (3), the end part of the positioning nail (7) can extend out of the bottom of the ruler body (1) by pressing the positioning nail (7), the second slider (4) is positioned on the right side of the first slider (3), a threaded hole is formed from the top end to the bottom end of the second slider (4), a screw rod (9) is assembled in the threaded hole, the top end of the screw rod (9) is fixedly connected with an angle measuring disc (10) positioned above the ruler body (1), the bottom end of the screw rod (9) is connected with a pen core (11), the ruler body (1) further comprises two fixing parts, one fixing part fastens the left ends of the two ruler bodies (1) together, the other fixing part fastens the right ends of the two ruler bodies (1) together, and scale lines for measuring the length are marked on the ruler body (1), the upper surface of the angle measuring disc (10) is marked with scale lines for measuring angles, a half volume of transparent colored liquid (12) is packaged in the angle measuring disc (10), the ruler body (1), the second sliding block (4), the guide rail (2) and the angle measuring disc (10) are all made of transparent plastics, when the pen core (11) is needed to be used for drawing a figure, the pen point of the pen core (11) can be screwed out from the bottom of the ruler body (1) by rotating the angle measuring disc (10), and the angle measuring disc (10) is tightly attached to the upper surface of the ruler body (1); the left end of two ruler bodies (1) all is equipped with left boss (13), is located the mounting of ruler body (1) left end is for only offering left boss upper shield (14) of a fixed slot, and two left boss (13) chucking are fixed in the fixed slot of left boss upper shield (14), the right-hand member of two ruler bodies (1) all is equipped with right boss (15), is located the mounting of ruler body (1) right-hand member is for offering right boss upper shield (16) of two fixed slots, and two right bosses (15) are blocked firmly respectively and are fixed in two fixed slots of right boss upper shield (16).

2. The multi-functional straightedge of claim 1, wherein: the upper and lower surface of left side boss upper cover (14) all with the upper and lower surface parallel and level of ruler body (1), the upper and lower surface of right side boss upper cover (16) all with the upper and lower surface parallel and level of ruler body (1), the preceding, back both sides of left side boss upper cover (14) all with the preceding, back both sides parallel and level of ruler body (1) respectively, the preceding, back both sides of right side boss upper cover (16) all with the preceding, back both sides parallel and level of ruler body (1) respectively.

3. The multi-functional straightedge of claim 2, wherein: the screw rod (9) is sleeved with a second spring (17), and the upper end and the lower end of the second spring (17) are respectively abutted against the lower surface of the angle measuring disc (10) and the upper surface of the guide rail (2).

4. The multi-functional straightedge of claim 3, wherein: the pen is characterized in that a clamping groove is formed in the bottom of the screw rod (9), and the pen core (11) is detachably installed in the clamping groove of the screw rod (9).

5. The multi-functional straightedge of claim 3, wherein: the pen is characterized in that the bottom of the screw rod (9) is fixedly connected with a clamping ring, and the pen core (11) is detachably arranged in the clamping ring.

6. The multifunctional straightedge of claim 4 or 5, wherein: the clamping hook (5) is made of a spring steel wire.

7. The multi-functional straightedge of claim 6, wherein: the scale mark of one of them ruler body (1) is shown in the inward flange of this ruler body (1), and the scale mark of another ruler body (1) is shown in the outward flange of this ruler body (1), the scale mark of angle measurement dish (10) marks in the edge of angle measurement dish (10) upper surface, 0 scale mark (10 a) and 90 scale mark (10 b) of angle measurement dish (10) all extend to the central point of angle measurement dish (10) from the edge of angle measurement dish (10), and work as when angle measurement dish (10) hug closely in ruler body (1), 0 scale mark (10 a) are on a parallel with the long limit of ruler body (1).

8. The multi-functional straightedge of claim 7, wherein: the ruler is characterized in that the positioning nails (7) are located at the zero scale lines of the ruler body (1), the top of the positioning nails (7) is fixedly connected with a turntable (18) which is convenient to rotate, and the turntable (18) is located above the ruler body (1).