CN113147236A

CN113147236A - Folding multifunctional teaching aid

Info

Publication number: CN113147236A
Application number: CN202110481043.6A
Authority: CN
Inventors: 鲍雨梅; 姜博鑫; 邹涛; 刘健
Original assignee: Zhijiang College of ZJUT
Current assignee: Zhijiang College of ZJUT
Priority date: 2021-04-30
Filing date: 2021-04-30
Publication date: 2021-07-23

Abstract

The invention discloses a folding type multifunctional teaching aid which comprises a rotating main shaft, a base ruler, a rotating ruler, a folding ruler and a clamping mechanism, wherein one end of the base ruler is fixedly connected with the side surface of the opposite bottom of the rotating main shaft; the sum of the lengths of the base ruler and the folding ruler is equal to the length of the rotary ruler. The multifunctional portable teaching aid integrates multiple functions, can realize the functions of circle drawing, straight line measurement and angle measurement, is convenient to carry, simple in structure, ingenious in design, stable in function and efficient in action, and solves the problems that the existing teaching aid is various in use and inconvenient to carry.

Description

Folding multifunctional teaching aid

Technical Field

The invention relates to the technical field of special tools for teacher teaching, in particular to a folding type multifunctional teaching aid.

Background

Although the compass, the ruler and the set square are still indispensable in the mathematical teaching of primary schools or middle schools even though the compass, the ruler and the set square enter the internet era, but the functions realized by the general teaching aid are independent, and the ruler is large in size and inconvenient to carry around at any time.

In the prior art, a compass ruler and a straight ruler for teaching are specially designed, but the compass ruler and the straight ruler are too complex, high in cost and not suitable for large-scale popularization; or is not suitable for carrying.

Disclosure of Invention

The invention aims to provide a folding multifunctional teaching aid, which aims to solve the problems in the prior art brought forward by the background technology.

In order to achieve the above purpose, the invention provides the following technical scheme:

a folding multifunctional teaching aid comprises a rotating main shaft, a base ruler, a rotating ruler, a folding ruler and a clamping mechanism, wherein one end of the base ruler is fixedly connected with the side face of the opposite bottom of the rotating main shaft, the top of one end of the rotating ruler is fixedly connected with a circular ring sleeve, and the circular ring sleeve is rotatably sleeved on the rotating main shaft and is positioned above the base ruler;

scales are arranged on one side of the base ruler, the rotary ruler and the folding ruler, the side with the scales is defined as a scale edge, and the side far away from the scale edge is defined as a back edge;

the scale edges of the base ruler and the rotary ruler are tangent to the circumference of the bottom surface of the rotary main shaft, and the straight lines of the back edges of the base ruler and the rotary ruler penetrate through the center of the bottom surface of the rotary main shaft, so that the scale edges of the rotary ruler are aligned with the scale edges of the base ruler when the rotary ruler is unfolded to form an angle of 180 degrees with the base ruler, and the back edge of the rotary ruler can be attached to the back edge of the base ruler when the rotary ruler is folded; one end of the back side of the rotary ruler, which is far away from the base ruler, is hinged with one end of the back side of the folding ruler, so that the scale edge of the folding ruler is aligned with the scale edge of the rotary ruler when the folding ruler is unfolded, and the back edge of the folding ruler is attached to the back edge of the rotary ruler when the folding ruler is folded; the sum of the lengths of the base ruler and the folding ruler is equal to the length of the rotary ruler;

the clamping mechanism comprises an L-shaped guide lock rod, a swing rod, a compression spring and a sliding button, a cavity is arranged in the end part of the folding rule close to the rotating rule, the L-shaped guide lock rod can be arranged in the cavity in a sliding mode along the length direction of the folding rule, a lock hole corresponding to the L-shaped guide lock rod is formed in the end face of the rotating rule close to the folding rule, and the front end of the L-shaped guide lock rod can extend out of the end face of the folding rule and is inserted into the lock hole; the sliding button is arranged outside the folding ruler and is fixedly connected with the L-shaped guide lock rod, and the compression spring is arranged between the tail end of the L-shaped guide lock rod and the end surface of the inner side of the cavity; one side of the L-shaped guide lock rod is provided with a lock groove thin plate, a lock groove is formed in the lock groove thin plate, the swing rod is arranged in the cavity in a swinging mode, and the free end of the swing rod can slide along the lock groove, so that the L-shaped guide lock rod can be clamped when extending out or retracting.

Preferably, the lock groove is a q-shaped groove composed of a straight guide groove, a first bent guide groove and a second bent guide groove, the straight guide groove is parallel to the folding ruler in the direction that the scale edge of the folding ruler faces downwards and the back edge of the folding ruler faces upwards, the first bent guide groove is connected below one end, close to the rotating ruler, of the straight guide groove, the other end of the first bent guide groove is connected with one end of the second bent guide groove, and the other end of the second bent guide groove is connected to the opposite middle part of the straight guide groove;

the relative middle part of the first guide bending groove is bent inwards, the outer side of the first guide bending groove is provided with three inflection points, namely an inflection point b, an inflection point d and an inflection point y from top to bottom; the inner side of the first guide bending groove is provided with three inflection points, namely an inflection point w, an inflection point c and an inflection point x from top to bottom; the inflection point w is higher than the inflection point b, and the inflection point d is higher than the inflection point c;

and an inner inflection point v and an outer inflection point u are arranged at the joint of the second guide bending groove and the guide straight groove, and the inflection point u is higher than the inflection point v.

Preferably, the rotating main shaft is in a cylindrical boss shape and sequentially comprises a bottom cylindrical section, a middle cylindrical section and a top cylindrical section, the outer diameters of the bottom cylindrical section, the middle cylindrical section and the top cylindrical section are gradually decreased from bottom to top, the base ruler is fixed on the outer side of the bottom cylindrical section, the middle cylindrical section is sleeved with the circular ring, and the end face, close to the rotating main shaft, of the rotating ruler is an arc surface and matched with the peripheral side of the bottom cylindrical section.

Preferably, the top cylindrical section is provided with an external thread, the thread of the top cylindrical section is matched with an angle mapping cone, the angle mapping cone is provided with an angle scale mark of 0-180 degrees, the annular sleeve is provided with an alignment line, and when the rotary ruler and the base ruler are in 180 degrees, the alignment line is aligned with the 180-degree scale mark on the angle mapping cone.

Preferably, the ring sleeve is provided with a radial threaded hole, and the inner thread of the radial threaded hole is matched with a rotating ruler locking screw.

Preferably, the rotary ruler and the folding ruler are hinged through a double-round-head connecting mechanism.

Preferably, a fixed point lifting mechanism is arranged in the rotating main shaft and comprises an adjusting knob, a limiting wafer, a screw, a quasi-heart contraction rod and a magnet; the middle of the rotating main shaft is sequentially provided with a screw rod through hole, a square guide hole and a magnet containing cavity from top to bottom along the axial direction, the adjusting knob is fixed at the end part of the screw rod, the limiting wafer is fixed on the screw rod, the screw rod penetrates through the screw rod through hole, the adjusting knob and the limiting wafer are respectively positioned above and below the screw rod through hole, the radial sizes of the adjusting knob and the limiting wafer are larger than those of the screw rod through hole, and the axial degree of freedom of the screw rod is 0; the quasi-centering shrinkage rod can be arranged in the square guide hole in a vertically sliding manner, and the cross section shape of the quasi-centering shrinkage rod is matched with the direction guide hole; the top of the quasi-centering shrinkage rod is provided with a threaded hole matched with the screw rod, and the bottom of the quasi-centering shrinkage rod is connected with the magnet.

Preferably, the back edges of the rotating ruler and the folding ruler are respectively provided with a chalk clip sliding groove, the chalk clip sliding groove is slidably provided with a chalk clip mechanism, the chalk clip mechanism comprises a chalk clip sliding tool, a chalk clip locking screw and a chalk locking screw which are matched with the chalk clip sliding groove, two parallel U-shaped chalk kits are arranged on the outer side of the chalk clip sliding tool, a chalk locking threaded hole is fixedly arranged between the two U-shaped chalk kits, and the chalk locking threaded hole is in threaded matching with the chalk locking screw; the chalk clamp sliding tool is provided with a chalk clamp locking threaded hole, and the chalk clamp locking threaded hole is in threaded matching with a chalk clamp locking screw.

Preferably, the chalk clip sliding groove comprises a strip-shaped groove which is respectively arranged at the top and the bottom of the rotating ruler and the folding ruler, the chalk clip sliding tool is U-shaped, and the opening end of the chalk clip sliding tool is inwards bent and matched with the strip-shaped groove.

Preferably, the end part scale edge of the base ruler far away from the rotating main shaft and the free end scale edge of the folding ruler are respectively provided with a chalk clip sliding short groove, and when the rotating ruler and the folding ruler are both in a folded state, the chalk clip sliding short grooves which slide the chalk clip mechanism to the base ruler and the folding ruler can fix the folded state.

Compared with the prior art, the invention has the advantages that: the multifunctional portable teaching aid integrates multiple functions, can realize the functions of circle drawing, straight line measurement and angle measurement, is convenient to carry, simple in structure, ingenious in design, stable in function and efficient in action, and solves the problems that the existing teaching aid is various in use and inconvenient to carry.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is an enlarged exploded view at a in fig. 1.

Fig. 3 is a schematic diagram of the overall explosive structure of the present invention.

Fig. 4 is a sectional view of the rotating main shaft of the present invention.

Fig. 5 is a schematic view showing the structure of the chucking mechanism of the present invention when it is extended.

Fig. 6 is a schematic view showing the structure of the chucking mechanism according to the present invention when retracted.

Fig. 7 is a schematic view of a inflection point of the locking groove at B of fig. 5 and 6 in the present invention.

Fig. 8 is a fragmentary schematic view of the locking groove of the present invention.

Fig. 9 is a partial cross-sectional end view of a folding rule according to the present invention.

Fig. 10 is a folded state view of the present invention.

Fig. 11 is a state view of the straightedge of the present invention.

Fig. 12 is an angle mapping state diagram of the present invention.

Fig. 13 is an enlarged schematic view of C in fig. 12.

Figure 14 is a state view of the compass of the present invention.

In the figure: 1. the method comprises the following steps of rotating a main shaft, 11, an adjusting knob, 12, a limiting wafer, 13, a screw rod, 14, an aligning shrinkage rod, 15, a magnet, 16 and an angle mapping cone; 2. a base ruler; 3. a rotating ruler 31, a circular ring sleeve 32, a rotating ruler locking screw 33 and a lock hole; 4. folding the ruler; 5. a chalk clamp mechanism 51, a chalk clamp sliding tool 52, a chalk clamp locking screw 53, a chalk locking screw 54, a U-shaped chalk kit 55 and a chalk clamp sliding short groove; 6. the double-round-head connecting mechanism 61, the double-round-head connecting block 62, the sub-screw 63 and the female sleeve; 7. the locking mechanism comprises a clamping mechanism, 71, an L-shaped guide locking rod, 72, a swing rod, 73, a compression spring, 74, a sliding button, 75, a locking groove, 76, a guide straight groove, 77, a first guide bent groove, 78 and a second guide bent groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further specifically described below by way of embodiments in combination with the accompanying drawings.

Example (b): a folding multifunctional teaching aid is shown in the figure and comprises a rotating main shaft 1, a base ruler 2, a rotating ruler 3 and a folding ruler 4, wherein the rotating main shaft 1 is in a cylindrical boss shape, is concentrically composed of three sections of cylinders with different diameters, and has progressively decreasing outer diameters from bottom to top, namely a bottom cylindrical section, a middle cylindrical section and a top cylindrical section; the one end fixed connection of base chi 2 is in the side of bottom cylinder section, changes the one end fixedly connected with ring cover 31 of chi 3, and is concrete, changes the tip fixed connection of chi 3 and establishes in the bottom of ring cover 31, and ring cover 31 can freely rotate ground cover and establish in middle cylinder section, and changes the terminal surface that chi 3 is close to rotation main shaft 1 and be the arc surface, and this arc surface matches with the circumference side of bottom cylinder section. Above-mentioned setting makes base chi 2 and commentaries on classics chi 3 revolute the rotation that moves main shaft 1 through ring cover 31 and can rotate relatively, and base chi 2 all corresponds with bottom cylinder section with the height of commentaries on classics chi 3 for the two highly uniform. The one end and the folding ruler 4 rotatable coupling of rotation main shaft 1 are kept away from to commentaries on classics chi 3, and the length sum of base chi 2 and folding ruler 4 is equivalent to the length of commentaries on classics chi 3 for base chi 2, commentaries on classics chi 3, folding ruler 4 can expand into a straight line, also can inwards fold base chi 2 and folding ruler 4 to with the laminating of commentaries on classics chi 3, length after folding is the length of commentaries on classics chi 3.

In this embodiment, scales are arranged on one side of the base ruler 2, the rotary ruler 3 and the folding ruler 4, and one side with scales is defined as a scale edge, and the other side is defined as a back edge; when the three parts are unfolded to form a straight line, the scale edges are positioned on the same side and are continuous.

In the structure, the scale edges of the base ruler 2 and the rotary ruler 3 are tangent to the circumference of the cylindrical section at the bottom of the rotary main shaft 1, the straight lines of the back edges of the base ruler 2 and the rotary ruler 3 penetrate through the center of the bottom of the rotary main shaft 1, so that the scale edges of the rotary ruler 3 are aligned with the scale edges of the base ruler 2 when the rotary ruler 3 is unfolded to form an angle of 180 degrees with the base ruler 2, and the back edge of the rotary ruler 3 can be attached to the back edge of the base ruler 2 when the rotary ruler is folded; the one end that base chi 2 was kept away from to the back of the body limit of commentaries on classics chi 3 is articulated with the back of the body limit one end of folding chi 4 for its scale limit aligns with the scale limit of commentaries on classics chi 3 when folding chi 4 expandes, and the back of the body limit of folding chi 4 is laminated with the back of the body limit of commentaries on classics chi 3 when folding.

In this embodiment, seted up radial screw hole on the ring cover 31, radial screw hole internal thread matches has the rotating ruler locking screw 32, makes it support on rotating main shaft 1 through screwing up rotating ruler locking screw 32, can fix the position of rotating ruler 3, can make rotating ruler 3 can the free rotation through unscrewing rotating ruler locking screw 32.

In this embodiment, the back edges of the rotating ruler 3 and the folding ruler 4 are respectively provided with a chalk clip sliding groove, and the chalk clip sliding grooves comprise strip-shaped grooves respectively arranged at the top and the bottom of the rotating ruler and the folding ruler; the chalk clip sliding groove is slidably provided with a chalk clip mechanism 5, the chalk clip mechanism 5 comprises a chalk clip sliding tool 51 matched with the chalk clip sliding groove, a chalk clip locking screw 52 and a chalk locking screw 53, the chalk clip sliding tool 51 is U-shaped, the opening end of the chalk clip sliding tool is bent inwards and matched with the strip-shaped groove, and the chalk clip sliding tool 51 enters the chalk clip sliding groove from the outer end part of the folding ruler 4 and can slide along the chalk clip sliding groove. Two parallel U-shaped chalk external members 54 are arranged on the outer side of the chalk clamp sliding tool 51, a chalk locking threaded hole is fixedly formed between the two U-shaped chalk external members 54 and is in threaded matching with the chalk locking screw 53, and after the chalk is installed on the U-shaped chalk external members 54, the chalk can be fixed by screwing the chalk locking screw 53; the chalk clip sliding tool 51 is provided with a chalk clip locking threaded hole which is in threaded matching with a chalk clip locking screw 52, and the chalk clip mechanism 5 can be fixed at any position on the rotary ruler 3 or the folding ruler 4 by screwing the chalk clip locking screw 52.

The end scale limit that the rotation main shaft 1 was kept away from to base chi 2 and the 4 free end scale limits of folding ruler are equipped with chalk clip slip short slot 55 respectively, when rotating chi 3 and folding ruler 4 all are in fold condition, chalk clip mechanism 5 can slide along chalk clip slip short slot 55 minizone, it can fix the fold condition to slide chalk clip mechanism 5 to base chi 2 and folding ruler 4's chalk clip slip short slot 55, specifically, can be in when the teaching aid is in the expansion condition with chalk clip mechanism 5 from folding ruler 4 or base chi 2's tip draw-in chalk clip slip short slot 55, it makes its removal to folding ruler 4 and base chi 2's centre and fixed through chalk clip locking screw 52 to remove chalk clip mechanism 5 after the teaching aid is folded, thereby fix the fold condition of teaching aid, prevent its expansion.

In the embodiment, the rotation of the rotating ruler 3 around the rotating main shaft 1 and the chalk clamp mechanism 5 can be used for drawing a circle, so that in order to avoid friction between the rotating ruler 3 and a black board during circle drawing, a fixed point lifting mechanism is arranged in the rotating main shaft 1, and comprises an adjusting knob 11, a limiting wafer 12, a screw 13, a quasi-heart contraction rod 14 and a magnet 15; a screw rod through hole, a square guide hole and a magnet containing cavity are sequentially arranged in the middle of the rotating main shaft 1 from top to bottom along the axial direction, an adjusting knob 11 is fixed at the end part of a screw rod 13, a limiting wafer 12 is fixed on the screw rod 13, the screw rod 13 penetrates through the screw rod through hole, the adjusting knob 11 and the limiting wafer 12 are respectively positioned above and below the screw rod through hole, the radial sizes of the adjusting knob 11 and the limiting wafer 12 are larger than those of the screw rod through hole, and the axial degree of freedom of the screw rod 13 is 0; the quasi-cardiac contraction rod 14 can be arranged in the square guide hole in a vertically sliding manner, and the cross section of the quasi-cardiac contraction rod 14 is matched with the square guide hole, so that the quasi-cardiac contraction rod 14 can only slide vertically but cannot rotate; screw hole with screw rod 13 matching is seted up at accurate heart shrink pole 14's top, accurate heart shrink pole 14's bottom and 15 fixed connection of magnet, it rotates to drive screw rod 13 through rotary adjusting knob 11, thereby it slides from top to bottom to drive accurate heart shrink pole 14, and then drive magnet 15 and reciprocate, can be held in magnet and hold the chamber when magnet 15 moves up, can make it be less than the bottom surface of rotating main shaft 1 when magnet 15 moves down, draw 15 attractions of magnet on the blackboard during the circle, there is certain clearance between commentaries on classics chi 3 and folding ruler 4 of teaching aid will and the blackboard, thereby the friction with the blackboard when having avoided drawing the circle.

The teaching aid of this embodiment still has the function of angle survey and drawing concurrently, particularly, the top cylinder section of rotating main shaft 1 is equipped with the external screw thread, and top cylinder section screw thread matching has angle survey and drawing circular cone 16, and angle survey and drawing circular cone 16 can also carry on spacingly to the ring cover 31 of its below simultaneously to when angle survey and drawing circular cone 16 is in extreme position, there is the clearance between the top terminal surface of angle survey and drawing circular cone 16 bottom surface and ring cover 31, in order to avoid its rotation that influences ring cover 31. The angle mapping cone 16 is provided with angle scale marks of 0-180 degrees, the annular sleeve 31 is provided with an alignment line, and when the rotary ruler 3 and the base ruler 2 form an angle of 180 degrees, the alignment line is aligned with the 180-degree scale marks on the angle mapping cone 16.

During angle measurement, the rotary ruler 3 and the folding ruler 4 are kept unfolded in a linear state, the rotary ruler locking screw 32 is loosened, the scale edge of the base ruler 2 is aligned to one side of the angle to be measured, the scale edges of the rotary ruler 3 and the folding ruler 4 are aligned to the other side of the angle to be measured, and then the angle corresponding to the angle scale on the angle mapping cone 16 and the scale mark on the circular sleeve 31 is observed, so that the angle measurement can be realized; through adjusting the angle between base chi 2 and the commentaries on classics chi 3, the angle that the angle scale on the angle survey and drawing circular cone 16 and the scale mark on the ring cover 31 correspond simultaneously, when reaching the angle value of required ruling, the locking changes chi locking screw 32, then puts the teaching aid on the blackboard and draws the both sides of required angle respectively along the scale limit of base chi 2 and the scale limit of commentaries on classics chi 3, can realize the ruling of angle.

In this embodiment, the rotary ruler 3 and the folding ruler 4 are hinged through the double-round-head connecting mechanism 6, and the double-round-head connecting mechanism 6 mainly comprises a double-round-head connecting block 61, a sub screw 62 and a female sleeve 63. Two through holes are arranged at proper positions of the double-round-head connecting block 61, an ear ring is respectively arranged at the upper part and the lower part of the end part of the rotary ruler 3 far away from the rotary main shaft 1, two through holes with the same diameter are arranged at proper positions of the ear ring, two mother sleeves 63 respectively penetrate through the through holes of the rotary ruler, the through holes of the double-round-head connecting block and the folding ruler from bottom to top, the outer circle of the mother sleeve 63 is in clearance fit with the through holes of the rotary ruler, the through holes of the double-round-head connecting block and the through holes of the folding ruler, an inner threaded hole is arranged at the upper end of the mother sleeve 63, a matching piece is arranged between the outer thread of the son screw 62 and the inner thread of the mother sleeve 63, the two son screws 62 are respectively screwed in the threaded holes of the mother sleeve 63 from top to bottom, the counter bores are arranged at the upper and lower surfaces of the two through holes of the rotary ruler 3 and the two through holes of the folding ruler 4, so that the son screw 62 and the cap end of the mother sleeve 63 are both in the counter bores, the double round head connecting block 61 enables the connection of the rotary ruler 3 and the folding ruler 4 to form a hinged relation through the connection of the sub screw 62 and the female sleeve 63.

In the structure, in order to enable the rotary ruler 3 and the folding ruler 4 to be relatively fixed after being unfolded and further be convenient to use as a straight ruler, a clamping mechanism 7 is arranged between the rotary ruler 3 and the folding ruler 4, the clamping mechanism 7 comprises an L-shaped guide locking rod 71, a swing rod 72, a compression spring 73 and a sliding button 74, wherein the L-shaped guide locking rod 71, the swing rod 72 and the compression spring 73 are arranged in a cavity at the end part of the folding ruler 4 close to the rotary ruler 3, specifically, the folding ruler 4 is provided with an upper part and a lower part, opposite surfaces of the two parts are respectively provided with hollows, and the hollows of the two parts form a cavity; after the clamping mechanism 7 is installed, the upper part and the lower part are fixedly connected. The L-shaped guide lock rod 71 can be arranged in the cavity in a sliding manner along the length direction of the folding rule 4, a lock hole 33 corresponding to the L-shaped guide lock rod 71 is formed in the end face, close to the folding rule 4, of the rotary rule 3, and when the folding rule 4 and the rotary rule 3 are unfolded, the front end of the L-shaped guide lock rod 71 can extend out of the end face of the folding rule and is inserted into the lock hole 33; the other end of the L-shaped guiding lock rod 71 passes through the side wall of the folding rule 4 and extends to the outside of the folding rule 4 to be fixedly connected with the sliding button 74, and a strip-shaped groove is formed in the side wall of the folding rule 4 for the L-shaped guiding lock rod 71 to move back and forth. A compression spring 73 is arranged between the tail end of the L-shaped guide lock rod 71 and the end surface of the inner side of the cavity, and when the L-shaped guide lock rod 71 moves backwards, the compression spring 73 is further compressed; a lock groove thin plate is arranged on one side of the L-shaped guide lock rod 71, and a lock groove 75 is formed in the lock groove thin plate; the swing rod 72 is swingably disposed in the cavity, specifically, one end of the swing rod 72 is hinged to a plane below the cavity of the folding ruler 4, so that the swing rod can swing in the horizontal direction, the free end of the swing rod 72 is bent downward by 90 degrees, so that the bent portion of the swing rod is located in the lock groove 75, and when the L-shaped guide lock rod 71 moves back and forth, the free end of the swing rod 72 can relatively slide along the lock groove 75 in the lock groove 75, and the swing rod 72 is driven to swing.

The lock groove 75 is specifically a q-shaped groove composed of a straight guide groove 76, a first bent guide groove 77 and a second bent guide groove 78, the straight guide groove 76 is parallel to the folding rule 4 with the direction of the folding rule 4 with the scale edge facing downward and the back edge facing upward as the reference, the first bent guide groove 77 is connected below one end of the straight guide groove 76 close to the rotary rule 3, the other end of the first bent guide groove 77 is connected with one end of the second bent guide groove 78, and the other end of the second bent guide groove 78 is connected to the opposite middle part of the straight guide groove 76.

A plurality of key point positions are arranged on the lock groove 75, and it should be noted that the "high" and "low" of the point positions are both based on the direction of the folding ruler 4 shown in fig. 7 when the scale edge faces downward and the back edge faces upward, and are only used for explaining the working principle of retraction and ejection of the L-shaped guide lock rod 71; the swing of the swing link 72 depends on the shape of the locking groove 75, and the free end of the swing link 72 slides in the locking groove 75 to swing the swing link 72 along with the linear reciprocating motion of the L-shaped guide locking lever 71.

Specifically, the opposite middle part of the first guide bending groove 77 is bent inward, and the outer side of the first guide bending groove 77 has three inflection points, which are an inflection point b, an inflection point d, and an inflection point y in sequence from top to bottom; the inner side of the first guide bending groove 77 is provided with three inflection points, namely an inflection point w, an inflection point c and an inflection point x from top to bottom; inflection point w is higher than inflection point b, and inflection point d is higher than inflection point c; the joint of the second guide bent groove 78 and the guide straight groove 76 has an inner inflection point v and an outer inflection point u, and the inflection point u is higher than the inflection point v.

When the rotary ruler 3 and the folding ruler 4 are unfolded from the folded state to be in a straight line, the free end of the swing rod 72 is initially positioned at the inflection point c of the lock groove 75, the compression spring 73 is in a compressed state, so that the L-shaped guide lock rod 71 has a tendency of extending outwards under the action of the compression spring 73, and the free end of the swing rod 72 abuts against the lock groove 75 at the inflection point c to prevent the lock groove 75 from extending. If the sliding button 76 slides rightwards based on the direction shown in fig. 7 to drive the L-shaped guide lock rod 71 to move rightwards, the compression spring 73 is further compressed, because the inflection point c is lower than the inflection point d, the free end of the swing rod 72 contacts the edge of the lock groove of the d-y section, and the free end of the swing rod 72 rotates clockwise for a certain angle from the horizontal position shown in the figure through the guidance of the d-y section until the free end of the swing rod 72 slides to the inflection point y; then the sliding button 74 is released, the L-shaped guiding lock bar 71 will move leftwards by the resilience of the compression spring 73, the free end of the swing rod 72 will slide along the second guiding bending groove 78, and then enter the guiding straight groove 76, i.e. the free end of the swing rod 72 slides from the inflection point y to the inflection point a at the most end through the inflection point z, and at this time, the L-shaped guiding lock bar 71 is inserted into the lock hole 33 of the rotary ruler, so as to clamp the rotary ruler 3 and the folding ruler 4.

When the rotary scale 3 and the folding scale 4 are folded from the unfolded state, the free end of the swing link 72 is initially positioned at the inflection point a of the lock groove 75, the sliding button 74 slides rightwards to drive the L-shaped guide lock bar 71 to move rightwards, and the free end of the swing link 72 moves leftwards relative to the straight guide groove 76 of the lock groove, it is noted that, since the inflection point u is higher than the inflection point v, the free end of the swing link 72 cannot slide towards the second guide bending groove 78 when the teaching aid is horizontally placed (only under the extreme condition that the scale edge faces downwards, the swing link 72 may slide into the second guide bending groove 78 under the action of the self gravity, however, according to the habit of most people, when the rotary scale 3 and the folding scale 4 are folded, the scale edge is generally not completely downwards, even under the downward posture of the scale edge, as long as the moving speed of the L-shaped guide lock bar 71 is not particularly slow, since the inflection point u is higher than v, theoretically, the free end of the swing link 72 will not slide into the second guiding bent slot 78 at that instant; further, even if the free end of the swing rod 72 slides into the second guiding bent groove 78 under extreme conditions, the sliding button 74 can be loosened to return to the initial position, and the teaching aid is operated again after adjusting the posture), the free end of the swing rod 72 slides to the leftmost end along the straight guiding groove 76 and then enters the first guiding bent groove 77, the free end of the swing rod 72 moves to the inflection point b and cannot move leftwards continuously because the inflection point b is lower than the inflection point w, then the sliding button 74 is loosened, the L-shaped guiding lock rod 71 moves leftwards through the rebounding action of the compression spring 73, the free end of the swing rod 72 contacts the 'w-c' section of the first guiding bent groove 77 and finally slides to the position of the inflection point c through the guiding of the 'w-c' end, and under the action of the compression spring 73, the free end of the swing rod 72 abuts against the lock groove 75 at the position of the inflection point c to prevent the L-shaped guiding lock rod 71 from moving, at this time, the L-shaped guiding lock rod 71 retracts into the cavity and does not extend out any more; in this process, the L-shaped guide lock rod 71 retracts, the folding ruler 4 can be folded, and then the chalk clamp mechanism is clamped between the scale edges of the folding ruler and the base ruler, so that the teaching aid is folded.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A folding multifunctional teaching aid is characterized by comprising a rotating main shaft, a base ruler, a rotating ruler, a folding ruler and a clamping mechanism, wherein one end of the base ruler is fixedly connected with the side surface of the opposite bottom of the rotating main shaft, the top of one end of the rotating ruler is fixedly connected with a ring sleeve, and the ring sleeve is rotatably sleeved on the rotating main shaft and is positioned above the base ruler;

2. The folding multifunctional teaching aid according to claim 1, wherein the locking groove is a q-shaped groove composed of a straight guiding groove, a first curved guiding groove and a second curved guiding groove, the straight guiding groove is parallel to the folding rule in the direction that the scale edge of the folding rule faces downwards and the back edge of the folding rule faces upwards, the first curved guiding groove is connected below one end of the straight guiding groove close to the rotating rule, the other end of the first curved guiding groove is connected with one end of the second curved guiding groove, and the other end of the second curved guiding groove is connected to the opposite middle part of the straight guiding groove;

3. The folding multifunctional teaching aid as claimed in claim 1, wherein the rotating main shaft is in the shape of a cylindrical boss, and comprises a bottom cylindrical section, a middle cylindrical section and a top cylindrical section with gradually decreasing outer diameters from bottom to top in sequence, the base ruler is fixed on the outer side of the bottom cylindrical section, the middle cylindrical section is sleeved with the circular ring, and the end surface of the rotating ruler, which is close to the rotating main shaft, is an arc surface and is matched with the peripheral side of the bottom cylindrical section.

4. A folding multi-functional teaching aid according to claim 3, characterized in that the top cylindrical section is provided with external threads, the top cylindrical section is threaded to match an angle mapping cone, the angle mapping cone is provided with angle graduations of 0 ° to 180 °, the ring sleeve is provided with alignment lines, and when the rotating ruler is 180 ° to the base ruler, the alignment lines are aligned with 180 ° graduations on the angle mapping cone.

5. A folding multifunctional teaching aid as claimed in claim 1, wherein the ring sleeve is provided with a radial threaded hole, and a rotary ruler locking screw is matched with the internal thread of the radial threaded hole.

6. A folding multi-functional teaching aid according to claim 1, wherein the rotary ruler and the folding ruler are hinged by a double round head connection.

7. A folding multifunctional teaching aid according to claim 1 or 3, wherein a fixed point lifting mechanism is arranged in the rotating main shaft, and comprises an adjusting knob, a limiting wafer, a screw rod, a centering rod and a magnet; the middle of the rotating main shaft is sequentially provided with a screw rod through hole, a square guide hole and a magnet containing cavity from top to bottom along the axial direction, the adjusting knob is fixed at the end part of the screw rod, the limiting wafer is fixed on the screw rod, the screw rod penetrates through the screw rod through hole, the adjusting knob and the limiting wafer are respectively positioned above and below the screw rod through hole, the radial sizes of the adjusting knob and the limiting wafer are larger than those of the screw rod through hole, and the axial degree of freedom of the screw rod is 0; the quasi-centering shrinkage rod can be arranged in the square guide hole in a vertically sliding manner, and the cross section shape of the quasi-centering shrinkage rod is matched with the direction guide hole; the top of the quasi-centering shrinkage rod is provided with a threaded hole matched with the screw rod, and the bottom of the quasi-centering shrinkage rod is connected with the magnet.

8. The folding multifunctional teaching aid as claimed in claim 1, wherein the back edges of the rotating ruler and the folding ruler are respectively provided with a chalk clip sliding groove, the chalk clip sliding groove is slidably provided with a chalk clip mechanism, the chalk clip mechanism comprises a chalk clip sliding tool, a chalk clip locking screw and a chalk locking screw which are matched with the chalk clip sliding groove, two parallel U-shaped chalk sleeves are arranged on the outer sides of the chalk clip sliding tool, a chalk locking threaded hole is fixedly arranged between the two U-shaped chalk sleeves, and the chalk locking threaded hole is in threaded matching with the chalk locking screw; the chalk clamp sliding tool is provided with a chalk clamp locking threaded hole, and the chalk clamp locking threaded hole is in threaded matching with a chalk clamp locking screw.

9. A folding multi-functional teaching aid according to claim 8, wherein the chalk clip sliding grooves include bar grooves on the top and bottom of the rotating rule and the folding rule, respectively, and the chalk clip sliding means is U-shaped with its open end bent inward and matching the bar grooves.

10. A folding multifunctional teaching aid as claimed in claim 9, wherein the end scale of the base ruler away from the main axis of rotation and the free end scale of the folding ruler are respectively provided with a chalk clip sliding short groove, and when the rotating ruler and the folding ruler are both in the folded state, the chalk clip sliding short grooves for sliding the chalk clip mechanism to the base ruler and the folding ruler can fix the folded state.